Baby keeps choking

So, we were getting the hang of this breastfeeding thing and had been doing great until a few days ago, when for some reason my right breast started flowing faster. Since then, the baby has been gulping and choking on my breast milk. We are 3 weeks, 2 days postpartum. I've tried the uphill feeding, but it doesn't seem to make much difference. It doesn't seem to be overactive letdown because it continues the entire breastfeeding session. Should I start block feeding and trying to ignore the right breast for one or two feedings? Should I start every feeding with the right breast so it doesn't end up as full? I hate seeing my little one choke and cough 3-4 times on that breast. What should I do? I read that it should regulate itself, but it seems to be getting worse instead of better.