I have been trying the PU/PD method for 4/5 days now and really seen improvements. I am able to put him down in bed and maybe after 2 or 3 pick ups he is able to relax and fall sleep.
Great that your seeing improvements! That's really great
If it were me, I would do it all in one go and get it done, rather than prolonging it for both of you. I would move him into his room and expect him to sleep there. I would stop feeding him at night, stop feeding him to sleep during the day. I would expect to have to soothe him and comfort him at night, but I would resolve not to feed him (easier said than done, I know!). I generally did not feed my LOs at night at this age but there were a handful of occasions, when ill or teething, when nothing else was the right choice, and then it certainly was the right thing for everyone concerned
I would plan ahead. Start this at the weekend or when there will be someone around so you can have a nap during the day. I would make provision for myself to be comfortable while soothing him. I have spent more than a few nights
lying on the floor in my LOs rooms with a pillow and a blanket, when they were sick or whatever. You could even bring a mattress in there and make yourself a bed.
One question - will he go back down at night for someone else who isn't feeding him? That might make it easier on him and you. Or at the least it would be a way of giving you a break for a night or two.
Another big question - what is his routine like? there could be a routine fix which will make this whole thing easier. could there be any medical reason for his frequent waking? Has he ever had a reflux diagnosis?