I'm so ashamed to be posting about sleep again. Everyone here was so supportive when I was struggling with my first kids' sleep but I know it got annoying. Whelp- here I am again.

Guys I'm so bad at this. And its my second time! I know that all of my son's sleep problems are my fault- he actually has, at times, been able to soothe himself and be more of an independent sleeper but I always just nurse him to sleep because its easy, and let him use me as a pacifier all night because I'm lazy and now it has become an intolerable mess and he's exhausted.

He's 6 months old. He's been in our room in a crib (on his belly) for about a month and a half now, after co-sleeping from birth. His nighttime sleep has always been bad, we're trying to separate nursing from sleep to help reduce wakings (he wakes up every 90 min-2 hours. There is no "long stretch." It has never been consistently better than that).
Lat night we tried to have my husband put him down, did the routine but with nursing moved to the beginning.

He cried (and by cried I mean screamed) for about 45 minutes- slept for twenty- screamed for another 30-slept maybe 15...this continued for 2.5 hours. My husband went in a couple times. Got him back to sleep once by playing guitar (for some reason he seems to respond well to loud music, but not just singing?). Finally at 9 I nursed him to sleep. He woke up at 11 and wouldn't go back in his crib. I tried three times and then my husband took over so I could get some sleep. At 3 I tried again to get him back in his crib. Nope, and I had to work today- So he slept in bed with me, latched on. I tried to take him off my nipple a couple times and he'd wake up and cry again.

All of this is to say- I need help. We did some sleep training with my daughter but she was never this upset.
He screams if we hold him, screams if we pat him, screams if we sing. The only thing that soothes him is nursing and its obviously not working. He's tired all day. His naps are crappy (after being really good most of the time).

Right now I feel like we are going to have to put him in his crib, turn off the monitor, sleep in the guest room and just set an alarm for midnight or something so I can go feed him.
That seems scary and not safe and cruel but I really am unsure what else to do.

My husband really struggles with helping because our son will just scream no matter what he does (except, apparently, loudly playing the guitar). I am struggling to be consistent because I'm operating on such sleep debt. But I can't keep doing this- its just ridiculous and increasingly unsafe for me to be driving. I also am nervous that this will result in him being a bad sleeper when he's older- he's SO upset by it but clearly has higher sleep needs.

Help?