Breastfeeding trouble

My son is 1wk old today and has been having issues latching and feeding off and on since birth. For the first 3-4 days he did awesome. Great outputs latched easily. Now he screams when I try to latch him. Screams and thrashes around at each breast, any time of day, any position. I’ve been pumping to supplement because he was jaundiced and had weight loss in the first few days and he doesn’t seem to have any issues taking my pumped milk. I had the ped check and there’s no signs of a tie. I’m at a loss of what to do. I never had issues with my daughter..