To be in tears over how destructive my 2.5 year old is?

Hey OP

I had 3 boys within 5 yrs...... it can be carnage.

Some pointers I used.....
Wear them out. We would go for a walk or to the park twice a day. Simple things like later today we are baking cakes I need you to help mummy at the shops buying what we need, or £2 to spend at the charity shop.

Have a plastic box where they have to put their drinks if they are in living room.

Several toy boxes but are rotated. IE Monday and Friday red toy box. Tues and Thurs blue toy box.

More importantly..... things will get broken, drinks will get knocked over. Kids are kids. At the end of the day you can think tonight well they are alive and fed 😘

My sympathies OP. I have a 2 yo and a 6mo and try as I might, fairly frequent toddler is creating chaos whilst I am doing some essential tasks like making food or feeding baby. I laugh at that oh-so-useful advice 'set toddler up with special feeding time basket whilst you relax on sofa with baby'. My toddler gave it one look, pulled all his books off the shelf, climbed on the dining table and threw the plant on the floor.
In an attempt to actually provide some advice, I'll share that I've found it helpful to limit the options of potential damage when I can't be directly next him or aren't in the mood to clear up, but not to remove offending item permanently, so he still gets chance to fulfil his requirement to do whatever it is. So no open cups most of the time, but occasionally I'll agree with plenty of reminders about not tipping it. He gets 2 chances to use it sensibly then it's gone, and I say cheerily, oh dear we'll put it away now, you'll help me clear up, and you can have another practice using it nicely later/tomorrow. Seems to be helping, or at least he now doesn't tantrum when I put the cup away because he trusts he'll get it again tomorrow and he sometimes doesn't pour it out, and I give tons of praise for that.

Poor you op.
You deffo have a Godzilla toddler there.
He'll be an amazing adult! 😁😁😁

I'm loving the sensory breaks / squeeze the sillies suggestions... Wish I'd known about that one back in the day.
My solution was to go to the woods for large chunks of the day. Any weather... Discomfort is relative. 🤣
We did Himalayan balsam bashing... Ripping up invasive plants that is... Omg that was therapeutic for all of us.
There was a lake, he made mud pies I sat on a log and bf baby.
Other stuff you do in woods.
Basically went feral. Can't say it was relaxing but at least the house was the same when we got back as when we left it.
But if you have 3 under 5... Respect. Hats off. Hope you survive it, but don't blame you for crying in the face of that onslaught. 🙏

Ignore...you are solving it with the vipers...

Different kids different temperaments.

My autistic kid threw everything they could down the stairs everyday after school. Too fucking knackered at the time to think of solutions...which I can now. (Lock everything up upstairs as well as downstairs)

Could he go to preschool more.

I mean I can’t honestly say I’ve met a child that seems as hyped up destructive as yours sounds. Does preschool have any possible concerns that maybe there is Sen at play.

They sometimes go through a stage of prefering to play with real things than toys. My son used to love emptying cupboards and pouring water. So he had "safe" cupboards in our kitchen and in both our mums' kitchens full of tupperware/non breakable items that he could empty. And I would give him a load of bowls/cups/jugs etc so he could pour water to his heart's content - either out in the garden or I'd put towels down for him to play on inside. My mum was very good at making him dens out of sheets in the garden or using the back of the sofa

I would get a large and high play pen to put him in.

Sew the sofa cushion zip tag to the cushion cover. (If not leather)

My dad used to sit in the playpen to work to protect his stuff from me.

It's a normal stage of toddlerhood. Not that that makes you want to throttle them any less. Just buy only plastic or wooden stuff and keep breathing. Only 6 months or so until he becomes a slightly more reasonable human being.

My living room was virtually empty at this point... didn't put much back in it. And had no garden...but if you do have one this advice is better.

I think we did a lot of water play in the bath.

We had indoor sand but if you have a thrower don't do sand at all. (Or yogurt)

Definitely hide sudocreme. It doesn't come out of carpets.

We had furniture made with lockable doors for our living room. (Same cost as sturdy premade furniture) Didn't have handles put on so they couldn't pull on the locks. We had a climber. Window locks on all windows.

Have you and your dh tried getting properly angry with him, OP? Kids are like dogs, either they're a little bit scared of you if they misbehave, or they're in control and everyone has to live with the ensuing chaos.

Look into dementia drink bottles too OP, they're anti spill. We use these. They are a one way suction valve. They're not fool proof but they have made life easier for us.

Really tricky, if you didn't have an older child I would have suggested stripping everything back but it does seem unfair for your older child to not have access to toys etc because you 2.5 year old can't be trusted.
I think for things like the juice/water, I would only be giving it to him at times you can supervise, you can't withhold something like that but just be really calm and immediately take it away when he spills it and try to get him to help clean it up with you.
Is your oldest child able to play in their bedroom so that you can separate out toys for your 4 year old and those for your 2.5 year old?
I recently also saw some advice about if a younger child is ruining train tracks for example whilst the older child is trying to play with them, to put the older child into a playpen with their toys so the younger child can't access them, rather than the other way around.
I feel like reducing the number of toys drastically (maybe hide them somewhere) might help, if he doesn't have several boxes & bags of things to empty then he might get bored of that quicker, also less for you to tidy up and he might understand the consequence of - if you destroy things, you don't get to play with them. Maybe give 1-2 toys a day and rotate them out. We hide the extras in the bottom of our wardrobe and do a weekly rotation.
He might be advanced & getting bored since he's so capable with the child locks and stair gates... or he might just be a frustrated destructive toddler, how's his communication skills?

Edited to add: at this stage I would probably accept that for a few years you don't get nice things like breakable soap dispensers, use a plastic one he can't break, foil his plans any way you can.
Also, my daughter loves packs of wet wipes, obsessed with pulling them all out, apparently a super fun game. She's not any where near the level of your son but I kept a pack of wipes marked as hers and when she's bored of pulling them all out, I just shove them back in and she can do it again another day.

We do regular breaks to "squeeze the sillies" out of our arms and legs. It either calms my son down or it gets him excited but distracted and we have a connection, both are a win.

Sensory breaks are great advice.

If you think he has higher levels of energy than a typical toddler and you're already getting in lots of movement during his day try adding some regulating activities.

Proprioception - activities against resistance e.g. pushing/pulling, crashing play, hanging from monkey bars/kneading dough/activities against resistance. Blowing bubbles/drinking through twisty straws.

Deep pressure - joint compressions/massage/foot squeezes.

I don't think my DS has any specific sensory needs other but responds well to leg/foot massage to help him calm down and loves to hang. Usually do them after a good run about.

Is this not normal 2 year old behaviour?

Kids at this age learn through cause and effect. They love it. It's like magic to them.

You cannot stop him from doing this but you can find safer and less messy ways of him doing this.

This might mean using plastic soap dispensers and removing loose cushions and making a wet table for him to explore pouring, and putting child locks on cupboards or rotating toys so that he only has access to a limited amount at a time.

My child is autistic and at 2.5 wouldn't have understood my frustrations, but he definitely did this stuff and we just had to redirect him, and he's 5 now and has learnt that when we want to do wet stuff we do it at the wet table, when he wants to undo a ball of yarn he's to wait for a grown up so we can play winding and unwinding. Back then we got a toy baby wipe box, that had dry wipes that could be put in and taken out. We made a busy board. We had science days where we would have activities that show him that sometimes you do something to an item and it can't be changed back to its original state, like kitchen roll in colourful soapy water.

It was exhausting, and I definitely didn't do things like this every day but once I knew it was the cause and effect that he was seeking and not just being a troublesome toddler it made life a lot easier to navigate.

You're not doing anything wrong. Three under five is relentless. Part of it will be normal toddler exploring, and as others have said, part of it is probably also totally normal jealousy of the baby.

Your eldest being in school soon will hopefully mean you will have a bit more time to concentrate just on him while the baby is napping, and fewer sibling fights to break up.

Would he sit on the sofa and listen to a story sometimes while you breastfeed, or is he too active? Sometimes that's a nice way of deflecting jealousy as they get your attention even while that baby is feeding.

Does he go to nursery? If not, do you have a local drop-off playgroup where he could go for a couple of mornings a week, just for two or three hours to give you a break and him some distraction? They often take children from 2.5.