How can I decrease milk supply on one side?

So my baby is 5 weeks old and my left breast seems to make her cough and choke every time she eats which scares the crap out of me. When she's coughing I pull my nipple out and my breast milk is spraying out. I only seem to have this problem on that breast how can I decrease my supply. I try using a hakkaa right before I feed with that breast but I feel like it's increasing my supply. Sometimes I don't have the hakkaa on hand so I try expressing for a minute or two and she still chokes. She also starts to get really pissed and grunts while she's eating. What can I do?