It's super hard in the moment, sorry you're going through it.

Something that helped for us was rotating who was up. My wife would pump a bottle and I would take the late night shift. So she'd go to bed and I'd stay up and then give baby the bottle so she could get at least 4-5 hours continuous sleep. Then she'd take the early morning shift and would get up with the baby so I could get 4-5 hours continuous sleep. That stretch of sleep made all the difference.

The baby will start to grow out of it and will start to sleep better. Hang in there, you've got this.