Sudden change in behaviour 3.5 year old

[Beks1989]

Hi im new to mumnset and hopefully someone can help me or give some tips/advice
So I have a 3.5 Yr old son who up until last week has been really easy going and the happiest little boy. He is awaiting austism diagnosis which is highly likely as he has all the signs but generally very happy with life.
Hes been attending nursery since September which he absolutely loves runs in without any bother every morning.
Last week he came home from nursery in tears and they said he had been really unsettled and getting upset at the smallest of things which is very unlike him and asked me if I knew I said he had a little cold but otherwise no idea they said he had thrown his dinner on the floor at lunch time.
Later that week he said to me nursery sad.
He has very limited language and communication but he does script back (delayed echolia) he said ( we don't throw food on the floor it's ridiculous look at the floor go away go away ) and he kept repeating that all weekend . He is refusing to leave the house to go any where . Won't even play in the garden just generally not him self . He's acting out throwing his meals on the floor at home im staying calm as don't want anymore upset . Hes refusing everything I cannot get him in his car seat to go anywhere as he's so big and strong and he's throwing a big hysterical tantrum at bedtime for the 1st time ever. I spoke to nursery and they dismissed getting angry which i knew they would and they said we will work on some ways help him at meal time (they are already aware of autism and are helping me on the route to assessments and a ehcp for school so really want him to finish his last 5 months there.
I have had to take him in kicking and screaming the last few days and I'm starting to feel I've lost my little boy for good we stayed in the house all day today and I felt on the verge of tears . His autism seems to be more obvious he's in his own world humming and wanting a dummy and to play on I pad .
Is this it now or will I get my child back I feel like his bubble of happiness and trust had gone .

Take him to the GP and get him checked out to rule out anything medical. Especially ear infections, if he's just got over a cold and is now refusing to eat. Ear issues can affect hearing and it may be that nursery seems noiser and more confusing or just that he's in pain.

Once you've ruled out physical causes, I would think if anything at nursery or home has changed - even if it's small (he's sitting in a different seat at lunchtime; a new child has joined the class but they've not even interacted yet), even if it's positive (we got a new car and he was excited). He may be reacting to or even processing the change.

I would also ask nursery to start an ABC chart or STAR (situation, trigger, action, response) diagram for any incidents of upset or challenging behaviour. That might pinpoint triggers.

@BusMumsHoliday’s post is good advice.

I would also go back to the nursery to discuss lunch times and how they are handling situations when dysregulated. Follow up verbal conversations with emails so you have a paper trail as evidence should you need it at a later date.

Where are you in the EHCP process?

Thank you for responding. I took him to the doctor last week and they were pretty rubbish tbh they said they couldn't see his ear drum as alot of wax his ears look clean to me so must be internal they said he doesn't need antibiotics.
Getting him to nursery today was hell partner helped me strap him in his car seat and he screamed hysterically all the way there and said go home mammy . He got to nursery gate and was pushing the door shut on the staff and other parents were standing there I started to get upset I know i shouldn't but I'm heartbroken I didn't let him see me upset
I had a chat in there office and they said he has settled down now and happy reading a book . There going to try an egg timer at lunch time as he likes to be in control a bit ocd with things. I have a meeting with nursery next week . They said ehcp should be ready for Sept they need to come out and do one more assessment this month .

Have you tried some PDA strategies?

Did the doctor recommend anything for the ear wax?

They said ehcp should be ready for Sept they need to come out and do one more assessment this month .

What week of the process are you on? You need to know so you can make sure the LA is sticking to the timescales. This is important in case you have to appeal.

As part of the EHCNA, has the LA sought advice and information from SALT and OT? As well as an ed psych?