Hi Honey,
Welcome to to the forum. So sorry to hear you're having a hard time. I agree with Becky, I do your DS is getting too much day sleep and that it is time to change his routine. I think his body clock is all mixed up Hun. For his age an example of what works for LO's who are still on 2 naps is this:
WU 7am
Nap 1 10.30 to 12.30 (cap this nap at 1.5/2 hours max)
Nap 2 3.30 to 4.00
BT 7pm.
I would suggest keeping his day sleep at 2 hours max but definitely no more than 2.5
At first it will be hard for him because his nights are so disturbed so he will be very over tired but then his nights should settle down, and of course the idea is to get him sleeping through the night.
A LO of your son's age shouldn't need any milk in the night at all. Although you could place a sippy in his cot for him to help himself. I would usually suggest that he is waking for the milk and so it is a viscous circle but I think he is also waking because he has had too much daytime sleep and he is UT which in turn causes OT because of all the NW, so it's probably a double edged sword.
Hun, if he is ever to sleep through the night in my opinion you need to go 'cold turkey' with the milk in the night. It seems to have become a 'prop' to help him get back to sleep, but if you combine the change of routine with stopping the milk things should right themselves in time. I have been there with my Son Sam when I foolishly started to feed him back to sleep for comfort when he was in pain through teething. He too, in the end was waking up to 6 times a night.
In the short term you are probably in for a bit of a rough ride, Sweetie, but in the long term you could be in for a lot of lovely sleep. I think him being in your room makes it harder to be honest. I would suggest you try the PU/PD method except at his age you use just the PD part. If you're not familiar with it here is a link:
http://babywhispererforums.com/index.php?topic=208990.0Let me know what you think
I would be happy to take you through the days to come and be there with any questions and support you need. If you decide to go for it you may need to push his 1st nap out slowly so we could talk about that before you started.
If your little fella has never been an Independent Sleeper, then that is also something that would be good to address but getting the routine right first is probably the best move.
This can all be done with consistency and determination Hun, and having a plan always makes you feel better already
(HUGS) to you
Being a Mammy is so rewarding but so tough at times
Vicki.x.