Sore nipple

My baby is two weeks and I’ve been breast feeding for about a week and a half. I stopped breastfeeding in the hospital because both nipples were sore but eventually started again because they felt better. We nurse with a nipple shield because that’s the only way he’ll latch. The problem I’m having now is that my left nipple is extremely sore. It started hurting when he ate and I just sat through it because it looks and sounds like he’s latched correctly, I just think he’s sucking way too hard. Now it’s too sore to do that. Would it be bad for my supply to only hand express in my left side and feed on the right until the other side isn’t sore? Are there ways to help it not be so sore quicker?