You poor thing. xoxo
There has been some great advice.

Something that I learnt in the last couple of weeks....
I have always fed to sleep too. I have been blessed with an excellent sleeper at night, but During the day this was the only time that I could get DS to sleep. I would gingerly carry him to his cot, and gently place him in careful not to disturb him, but then he would wake with really bad wind.....because I wasn't really burping him, this is a bit of a problem with feeding to sleep.

DS goes to creche one day a week, and the other week I went in during lunch as I usually do, and fed him. I then burped him, and handed him back to his carer (my dear friends mother, i really lucky)to put him to bed....and I watched.....

She talked to him gently and told him it was time for bed, she stripped him down to his singlet and nappy, and swaddled him in a sheet, and she put down in his cot facing away from her on his side, so he was looking at the wall, and she tucked his blankets in...and then walked away. He was asleep in 2 minutes flat and slept soundly for 2 hours. He didn't cry or anything, he wiggled for a minute and that was it. Apparantly he does that every day he is at creche....they found that the more they stood there trying to pat him etc, the worse he got and the more worked up he became.

It was then that I realised that he had me wrapped around his little finger....he knew if he cried that I would just get him up and feed him more etc etc, and then the cycle begins.
So I have been putting him down wide awake, and I make sure that all his wind is up.
I face him against the wall, and resist his wiggles and tuck him in. And amazingly off he goes to sleep!! And he has a deeper sleep because he has settled himself. Being consistent has been the key.

He has recently started waking once during the night, and same thing, I feed him, burp him and put him back in wide awake and off he goes.

I also find that if we are out, I do the same in the pram, put him in on his side and he instantly knows it is sleep time, and doesn't bother fighting it too much.

I am not sure if this will be any help, because it seems like you have tried so much, but I am thinking of you. xoxo