Sleeping Question

At 2 months old my baby was sleeping through the night. This only lasted about 3-4 weeks and he started waking up again, but only occasionaly. He has gradually regressed (he's now almost 5 months old) and now he is waking up every night. I'll go in and feed him and then he'll be awake for about an hour talking to himself until he falls back asleep. I know he can get himself to sleep and when i feed him he takes about 6 oz, so it seems like he's hungry. On the other hand, I know he's capable of sleeping through the night (occasionally he'll still sleep 12 hrs w/o waking). I had planed on letting him do whatever he needs to until he was 6 months and then if he still wasn't sleeping through the night then letting him cry it out or doing something. I am not sure I can wait that long, the no sleep is getting to me and I'm constantly crabby with my 2 yr old and baby.

So, any ideas? Cry it out now? Gradually reduce the amount of formula until it's down to nothing? HELP! I'm going crazy.  

Come on, someone has to have an opinion...

when is his last bottle for the night ? Riley is 2 months and sometimes he will sleep from 10:30-5:00,, mostly it's when he has tummy aches and is crying alot before bed, i guess it tires him out,, he eats 5 oz with cereal, i know thats alot but he has acid reflux and the cereal helps.. but i usually bath him at 8-9,, and when he gets out i feed him, i try and make him wait for his bottle but by 9 he is ready, sometimes i give him little tummies to help with gas after the bottle and that settles his stomach,, i keep him up till about 10 and then if he is still awake i just put him in his bed with his mobile and music on, it kicks off after about 5 min but usually by then he is asleep.. sometimes he will sleep all night and others he will be up 2-3 hours, but after every bottle i burp and put him straight in his bed, he doesn't cry himself to sleep but he wines,, most of the time he is half asleep and just fighting it ,,, but i usually wait 5-10 min and go check on him,, if he still isn't sleeping, i put him on my chest and lay in bed and that always puts him to sleep within minutes