6 M/O breastfeeding constantly at night

[Tippertruck]

Hi I’m new and don’t understand the acronyms.

2 children, 2nd baby is 6 months old. We co-sleep. He is breastfed, he has a good feed to sleep between 7-8pm, usually sleeps good for 3 hours and then is literally up every 45 mins or more. He is feeding, I’m exhausted and I don’t know what to do. I’ve trying sitting up to feed him but this doesn’t make a difference. Any advice or tips or help would be great. I formula fed my first child due to milk allergy/tongue tie and my mental health, so this is my first time breastfeeding for longer than 2 weeks.
Also baby doesn’t take a dummy, and I try and give him a formula feed once a day and I need to wean off boob as going back to work and I struggle to express.

Are you able to feed lying down, or are you already doing that? Does it seem likes he’s comfort nursing while still sleepy/asleep, or is it “proper” feeding? I cosleep with my 1yo - have done every night since 3 months - and she basically comfort nurses throughout the night all night. It is very tiring, and I think it’s just part and parcel of cosleeping with a breastfed baby (although it does seem like some are less into comfort nursing than others. Mine does it A LOT, day and night). So, no real advice other than to try side-lying feeds if you don’t already as you can get back to sleep (ish) yourself like that.

The alternative is baby goes into their own room and dad goes to do settles that aren't feeds, and then you breastfeed at 2am and 5am (or whatever works for you). Also crack.on with solids and make the evening meal calorific - I used to give mine porridge oats with a bit of peanut butter stirred in.