hiya, my lo is 1 and I'm in the same position. It started at 6months when I had to wean him off boobing to sleep. The problem has always been that he does not keep still so I had to pretty much hold him down so he could go to sleep. Otherwise he would end up banging his head, and he'd get ridiculously OT because after an hour he's still be awake so i'd have to APOP him anyway. Now I want to leave him with a child minder but I can't expect her to hold him while he goes to sleep, leaving her other kids on their own.
I've tried gradual withdrawal but the process is taking too long. So, as off yesterday I started the pd at bedtime. I think its the only way. It went on for about 20mins by which time he was very upset and exhausted, but he finally went to sleep and I left the room. I'm going to do it again tonight and for as long as it takes. I know its hard and I understand how you feel, but like you said you don't want to be doing it when he's six (I have friends who are the same and I swore I would sleep train F before this happened!). I remember what it was like getting him off boobing to sleep and believe me, last night was nothing in comparison. Plus I know from that experience that every night is better and better until they are happy to do it the new way. Even if takes 2.5 months, like Jem88 says, thats not (I assume) 2.5 months of screaming and being upset every night (I hope!).
Do you want me to keep you updated on how I go? I know in the past I've found it really helpful to see someone going through what I'm going through. If not I hope soemone on here can give you (us!) some more practical advise. Good luck! x