A toughie! My DS is also co-sleeping and feeding two to three times a night. Those big nights of constant feeding are killers! Usually I've noticed he feeds like that and then comes down with a head cold, so maybe he has a sore throat and the extra feeding soothes it. Lately I've been getting him to sleep at night and, if I haven't fallen asleep too, I get up and have some "me time" and then I've been trialing going to bed in the spare room. When DS wakes up and gives a little cry, I wait to see if he settles again. If he doesn't then I move back to bed with him. I work full time so the day carer gets him to sleep on one of those little kids sofa chairs that fold out. I have had zero luck getting him to sleep at home during the day on ours, so like you, I let him sleep on the bed. I've been thinking of making a more serious attempt at getting him to sleep in his cot but I have also been thinking of converting it to a toddler bed. Not much help, I'm sorry, but I'm interested to see what advice you get!