Needing advice

My daughter is 10 weeks old. She was born 6 weeks early and was healthy. The only issue we have with her is that she eats every 1-2 hours and its only 2 ounces. My question is how can i get her to eat more and less frequent? Its very hard to get anything done when i am always feeding a baby. She is the best baby but i feel like she is not getting enough. If i make a 4 ounce bottle she will vomit if she eats more than 2.5. So we are wasting a ton of formula a day. Any advice? Please and thank you