Getting extremely hard to feed him

For some reason late at night and early mornings he has been crying and screaming murder when I try to feed him! It's so nerve wrecking because I know he's hungry but he's too busy kicking and moving so his head isn't still enough to latch on. I just tried to supplement him formula so he wouldn't starve but he gagged each time I gave it to him. He cries to the point where I literally want to just walk away most times because idk what else to do....