Letdown too much for baby.

Hello all,

My baby is now 5 weeks, he was born with low blood sugar and then jaundice so had to stay in hospital for few days, he was fed formula and the I expressed and fed him. Then I started pumping as he would not latch more than 5 minutes and sleep. Due to pumping my supply increased and so did my letdown. I want to breastfeed him but now the letdown is so much that he is not able to take it. He latches less than 10 minutes and then refuses, sometimes is fussy aswell. I want to completely breastfeed him, please help me what should I do?