i'm currently sitting listening to my 15month DS crying his heart out while DH tries to get him to sleep. it's making me cry too.
My DS used to be a great sleeper and go to bed/sleep really easily till he was about 11months. Then he started getting very clingy to me and getting serious separation anxiety, and at that time started having trouble settling himself to sleep. As soon as I made a move towards the door he would immediately stand up in his cot and start crying. If I came back he would soon stop crying and just sit looking at me with tears running down his face. I didn't want to try CC as it felt too harsh when he sounded so distraught and upset, even though my DH was in favour.
So I ended up nursing him till sleepy (still BF) then putting him to bed and stroking his head and back till he fell asleep, while getting a very sore back. Meanwhile I was going through books and websites trying to find suggestions and eventually found a really helpful thread on MN started by Nectarina on 29 Jan 2012, entitled "what worked for us. Hope it helps". I don't know how to link to it but someone else might be able to. It suggests staying with the DC but allowing it to settle itself to sleep, so not rocking to sleep, or nursing or cuddling, not picking it up, but comforting by talking or patting if DC gets very upset, until calmed, then sitting down and just doing your own thing. I really highly recommend you try and find this thread and see if you can follow it as it helped me.
There was some progress, and DS did start falling asleep within 20-30 minutes most nights, with me just sitting in his room, playing on my phone, talking to him if he started crying or patting him, then moving away again. So all was going well until a few weeks ago when he was ill with a vomiting bug and teething, and he is now taking over an hour to fall asleep which is really tiring and I'm struggling. Hence why DH is now taking a turn, but despite me asking him to stay in the room with DS, DH insists on trying to leave the room hence the crying I'm listening to, then goes back in after a few minutes if he hasn't stopped. Which to be honest I find so against what I believe in that I'd rather do it myself if I wasn't getting so tired of being stuck in DS's room all evening. So now not sure what to do other than keep trying with what I'm doing and hope it gets better as DS is starting to get less clingy during the day. Sorry - not such a positive outcome for us at the moment but I have had some improvement till illness struck.