My 8 month old, and my now 2 year old both had reflux and problems sleeping. If you can afford it, get a Graco Sweetpeace Soother. The baby can sleep in her carseat, and the motion makes her move so that she feels like she is in a car moving. The angle is higher than the recommended 30 deg, but its good for the baby. This was the only way both of my kids would sleep, we even had to buy the bigger carseat when they grew too big for the snugride, but I have a 26 pound 8 month old.
I agree, add the Prevacid, and try switching foods. Neither one of my kiddos could have dairy of any kind, nor breastmilk either. I couldn't even eat any while I was pregnant! DD is allergic to not only dairy, but soy too. They both had to be on Similac Alimentum for food. Also, putting a little rice or oatmeal in her bottle will help calm the tummy and help the reflux. My doc told me to, and it really helps.
I think if she is in less pain, she will be better able to sleep. You might still need to do some sleep training, but this should help. If you can put the soother in your room, then maybe she can sense that you are near by, but not need you to hold her. Also, the teething thing makes it hard to sleep too. Have you tried Hyland's teething pills? those help a lot, as does baby orajel and tylenol. If I can help more, please let me know, I have been there and I feel for you mama!!