Try using the playtex nurser bottles. You can push all the air out of the bag and then all the baby can suck in is the fluid inside the bag. Theres also another bottle that is almost in an "L" shape. I can't think of the name of it but it is suppose to keep all the air at the top of the bottle. I used the playtex with my daughter and am now using it with my son. I think they are the best ones on the market.
I would make sure that you are firmly holding the bottle to the mouth and not at an angle that will allow the nipple to be pulled out with the least movement to the bottle. Make sure you burp plenty while she is eating, and this will lessen the air in the tummy, and you can feed some more. My last one was like this, for a while, and holding the bottle firmly fixed the problem. Hope this helps, good luck to you.
I would call the Dr. Right away or take her to the nearest ER room to be checked out.