breastfeeding tips?

My son was born at 36.1 weeks, at first had some issues with blood sugar and body temp. So I never really got a chance to breast feed the first few days of his life. It was constant pumping and 24 calorie formula. Now that were home I try to breast feed, I know for a fact I make enough because I can pump 8 oz in one sitting, but it seems when I try to feed him he screams bloody murder and pushes my breast away after a few moments of eating. His latch is great for those first few seconds then its all down hill, he does this angry shake back and forth with his mouth. I've trued so many different positions, tried using a bottle for a few suckles then switching, I've had a lactation consultant help but nothing seems to work. Any ideas? I'm at that point of giving up 😭😭