Just a piece of advice, don't give up right away. My son had trouble with his latch, keeping his weight up, gas, reflux, colic, he was feeding every hour but falling asleep on the breast. He was burning more calories than he was taking in and feeding hourly to try and make up for what he wasn't taking in. He could stick his tongue out, but he couldn't move it up and down to transfer milk...and it turned out that he had a tongue tie. They're actually very common and the number one cause of breastfeeding difficulties. Because of the formula generation. pediatricians were not taught how to properly diagnose anything other than the classic severe tie, but the truth is, minor ties can cause huge issues, and severe ones could cause none. Untreated ties cause breastfeeding difficulties, tooth decay, and speech issues.
Take them to a pediatric dentist or Preferred Provider for diagnosis and treatment first, instead of skipping to formula if you want to keep your breastfeeding relationship going. Three NICU nurses and a pediatrician missed my son's ties and his caused him to be hospitalized 3 times back in NICU in this first 4 weeks of life. 5th week, I took him to a breastfeeding guru in Toronto (Dr. Newman, who is a preferred provider). He found the tie, clipped it right there, and we're been breastfeeding now for just over a year.