Not had time to read all the replies, but felt I had to give a more positive reponse to CC! Our DD (now 22 months) slept badly unil 1, then after a few decent months got worse again for a bit, so we did CC at about 18 months ish. obviously that's a lot older than you've done it, and not sure if i could have done it that young, but I definitely don't regret doing it.
The first night was hellish ( but asleep in about 45 mins), the second only took a bit less time and by the third I don't think we even went back in. I have a few friends who have done it (one at 9 months and her baby always seemed so much happier after that - must have been so tired before). However, I was always told you were supposed to gradaully increase he intervals - i.e. wait 5 mins, then 10, then 15. I felt 5 mins was a bit long, so we did it in 3 min intervals - 3, then 6 then 9, then 12 - don;t think we ever had to use more than that. Could you try that? However, perhaps as you have been co-sleeping and your baby is younger thaere could be some sort of middle ground - not sure what though - we just sort of muddled along!
As for co-sleeping, I've always hated the idea of doing that (and since coming on here felt bad about feeling that way as everyone seems to pro it) but on the few occasions we've resorted to it, none of the 3 of us have slept much, and I know I couldn;t have coped mentally with having no personal space at all (night is the only time when you are on maternity leave as it is!).
Do what feels right for you, but give it time.