I would see the doctor about another formula - one that is lactose free and broken down some like Enfamil Nutramigen:
http://store.enfamil.com/enfamil_nutramigen_lipil.html This formula is hypoallergenic, lactose-free, sucrose-free. I know you live in a place where this sorta thing may be difficult to get but I think it may be possible if you ask the manager of your drug store or market where you buy such things. You can also order off Ebay.
Anyhow, like I was saying above - its not fair to him to start trying to sleep train him if he is in pain. His pain could also be what is causing him to wake up, know what I mean? I am only speaking from experience. The key will be to keep trying formulas til you find one that works for his tummy AND doesn't cause loose stools. What meds is he getting again?
At almost 5m you want to aim for something like this:
E: 7.00 wake up and feed
A: from end of feed til 845 then wind down
S: 9.00 sleep (for 1.5-2hr nap)
E: 11.00 feed
A: and of feed til 1245p then wind down
S: 1.00sleep (1.5-2hr nap)
E: 3.00 feed
A: end of feed til 445p then wind down
S: 5.00 catnap 30-40m
E: 6p feed
A: bath or whatever
S: 645/7pm bed
E: 10 or 11pm dreamfeed (until 7 or 8mths or whenever solid food is firmly established)
This is just what is suggested. Now, if he does a short nap - you will have to put him down for the next nap earlier then usual to avoid him becoming overtired. Watch his cues, always put him down if he is showing sleepy cues regardless of what time it is. His short napping could be from the dummy, or cause he is hungry, or cause he is overtired - its hard to know.
Also, I think I mentioned before you may have to try small feeds more frequently until his reflux is in better control. If this is the case, EASY may become EAESY - and that is ok too.
You can use pat/shh (use rub/shh) with a dummy - you can use it to help him settle if he can't by himself. Stay away from putting him to sleep with it if possible. I would just stay away from any hardcore sleep training until he isn't hurting and is eating properly. He was eating 23ish ounces a day, so you know he can/wants to do that. The mission will be to try and find a formula that works well for him, which Nutramigen seems to be the one, no lactose and hypoallergenic - the two things he needs. Talk to you doctor about what they think, ask your store if they can order it - and check Ebay for it.
Im sorry things are hard still. It takes a while to find the right combo. After that you can do the sleep training - but even if you were to remove the paci and sleep train now, Im fairly certain it wouldn't work because he will have a need that isn't being met - either pain or hunger.
Love,
Zoey