My Baby Won't Breastfeed at Night!

Has this ever happened to anyone? We have struggled with nursing since day one, but i got his lip tie fixed last week and it seems like he's getting the hang of it now, but not at night! I keep trying and he just screams, but during the day he's way better! I don't know what to do; I'm soooo sick of getting up to feed him, get him back to sleep, then go pump. By the time I'm done and back in bed, it's almost time for him to eat again and I hardly get any sleep!