Hi J.~
My daughter went through the same thing, and there are days that she still doesn't sleep through!! (She is now 17 months) I live in an apartment and I didn't want to wake the neighbors, so I would run into her room as soon as I heard her make a peep. I found that this was the worst thing that I could do!! I also found that eventhough the Dr.'s say "Back to sleep" it was keeping her up because she would get startled when she was drifting off to sleep. We started to put her on her belly and she slept a little longer (4 hours or so at a time), and eventually we had to just let her "cry it out!!" It took about 3-4 nights and it was painful, but we knew that we were doing the very BEST for her by allowing her to fall asleep on her own and settle herself down. We set up a bedtime routine. She gets a bath @ 7:00 and we also use the Johnson and Johnson night time bath wash, shampoo, and lotion. Then we put P.J.'s on. She gets her hair then teeth brushed. A story and warm milk. We play the same CD for her everynight.(We turn it on when we take her into the room to get P.J.'s on, and leave it on repeat so if she does wake up she knows that it is still bedtime) The CD just gives her a cue that it is getting time to wind down for bed. Since we did the "cry it out" A.K.A "The nights of hell" and really stuck to this schedule she has slept almost EVERY night straight through, and it is FABULOUS!!! It is tough to listen to her cry, but just remember that you are doing what is BEST:) Hope this helps, sorry it is SO long and detailed!!
-L.