Everything is ruined and I'm so horrible

Everything just gets worse and worse. the 4 month sleep regression has hit us, it's been two weeks now and the longest stretch baby has had is 1hr and a half, the longest stretch I've had is probably 40 minutes. I'm so miserable, I just want to sleep. I've tried everything. I track his wake windows and although he flat out refused naps at the start of this, he now naps on queue. He has a good bedtime routine, he's well fed, he's generally really happy til night time and then he just changes. There's no hope getting him in his cot, the most he'll go in there is 12 minutes hahahahaha.... I have been timing. So we co sleep and it hurts and I'm miserable but we just do it. But it doesn't keep him down. So he wakes up and I cry and it takes about 30 mins to settle him. Or sometimes he can't be settled like tonight, where he's been awake for 2 hours and I've tried everything. And tonight I screamed at him. It was horrible. I literally just screamed in frustration. He looked shocked then kept on crying. I screamed again and said I hated him, and that everything is ruined now.... And it is, honestly. My life is so fucked. But it's not his fault, he's a baby that I chose to have. And I do love him and I feel like such a monster, but I also feel numb. I let him cry it out too today, which is something I was very against. I ended up picking him up after about 15 minutes but not because I felt bad (I felt numb), but because he was too noisy for me too sleep. This sleep regression feels unending and I don't think I'll ever be happy again. When I've looked online, nobody else's sleep regressions seem as bad as this? So I feel like I have no hope. And I don't know why I react so badly to not sleeping. My boyfriend is so chilled, he's been so helpful and nice but then the second I get that screaming baby in my arms I just freak out. I thought I'd be such a good mummy , not this angry screaming monster.