Oh, my DS went through a pretty painful phase like this around 7/8months. It would take him ages to settle, then I'd be in and out over and over until we went to bed with him, (about 11pm) where he'd proceed to squirm and faff.
My 11 mo is taken through the same sequence of events every night around the same time (depending on his nap). We tidy up, bath, go to bed with a book, then it's lights out. I stay with him while he falls asleep (we co-sleep) and sometimes he feeds to sleep (he is breastfed) though often he has his milk then makes himself comfortable and drifts off. I am reassuring but not playful; if he sits up or starts crawling around, I gently lie him back down, but I don't talk, play, get annoyed or do anything except look like I'm going to sleep.
This seems to work for us, though during developmental phases it can take a while for him to drift off, and he might need resettling lots. He is quite a good sleeper - I'm rarely up before 7.30 though when he was younger we'd be up anytime from 6. Developmental phases are predictable and far less maddening if you know about them - have you read The Wonder Weeks? It details the whens and whats of developmental phases and soothes your panic when it seems like your baby will never sleep again.
As for controlled crying, I am in the UNDER NO CIRCUMSTANCES camp, because I have read books citing lots of research showing that while it might 'work' for the parents in the short term (i.e. baby stops crying for mum at night) it has negative long-term effects on the baby's brain and relationships. Why Love Matters is a good book for this, or What Every Parent Needs to Know which is a lighter read. Or Your Baby and Child by Penelope Leach, which iirc doesn't do the heavy handed research argument but does point out that the most significant lesson of cc for the baby is that it's pointless crying for mum.
When I've read other Help! My Baby Can't Sleep - Am Hallucinating! threads the No Cry Sleep Solution always gets honourable mentions, so it might be worth getting. My advice from my (one baby!!!) limited experience is to always act as if you totally expect him to go to sleep at the allotted time, always do the same sequence of events (we even read the same book most of the time - because we travel about a lot and I want to replicate our home routine in strange beds), act like a presence but not a playmate after 'lights out' and never show your panic, frustration or uncertainty about the whole thing when he is having a wobble.
I know it's awful when you feel sleep deprived and there seems to be no end in sight, but your baby will sleep at night and you will get through these sleep deprived months. My baby is only a few months older than yours and what I know from these extra months is - it goes in the blink of an eye. Everything changes so very quickly! In the meantime, is it possible for someone to help you out in the day a bit so you could grab a few naps? or could you go to bed a few times at the same time as your son to do some catch-up until he starts settling again?
Good luck x