Try to feed him when he is drowsy, right after he wakes up or before his nap and so on. Feed him in a silent room without tv or phone, they start to be distracted by every noise at this age

I'm sorry you're going through this hun, I struggled to breastfeed my daughter and eventually had to switch to formula. If you want to try out formula and you see how he does you could always call his pediatrician and ask them for some samples. They're not as big as the ones you get in the store but they're not too small either and they're free!! I used to get 4 cans every time I went to the pediatrician

Wic provides formula. It really helped me out. Even if you use to supplement.