CC saved my sanity, twice.
DD woke every 45mins. I'd have to get up, rock her, hold her for long enough to ensure she was asleep, and then put her back (which gave me approx 30mins sleep). Her other trick was to only wake up once, but stay awake for three or four hours, and I'd have to rock her the whole time or she'd scream the place down. We got to 14 months and I was on the verge of a breakdown. Co-sleeping did fuck all, because I still had to sit up and rock her. If I put her in our bed she'd kick me, shuffle around, stare at me all night... not restful for anyone.
Four nights of CC (1min intervals) and she was going to sleep in minutes and staying that way all night long. It was a miracle. She was happier, DH and I were happier, I no longer fell asleep mid sentence.
Then we had DS. He had to be rocked, by me, for every nap and bedtime. It was fine at first but then he started the slapping, hair pulling, scratching my neck... He was waking up every 30mins, nobody else could get him to sleep, and it was ruining my relationship with DD. Co-sleeping didn't work for him either, for the same reasons (but he was more violent!), and I just snapped and went for it. He was 8mo and it took him two nights. Everyone was happier and DD wasn't shattered at school.
They're 6 and 18mo now, and for the most part we all sleep. They have their bad dreams etc, but it doesn't take much more than a quick pat or hug to settle them. If they're ill they come in our bed, but they SLEEP.
Nobody WANTS to do CC, and it doesn't work for every child, but if it does then it's absolutely life changing. I remember someone once posted that surely it's just as cruel to let your baby continually get awful sleep, than it is to try something like CC which might just work. Babies and toddlers need good quality sleep, with as few interruptions as possible, just like parents do.
OP, I wish you the best of luck and hope you start getting some rest soon!