Baby choking on my letdown?

My son is almost 10 weeks old and he seriously struggles with my letdown. He starts choking almost every time at least once (which scares the crap out of me) so i am always prepared to pick him up and start aggressively burping him. I can hear him just gulping and struggling to catch a breath. Also, as a result he has horrible gas, spit up, and hiccups.

We saw a lactation consultant when he was about 2 weeks old and she said it was normal and should improve in a few weeks as my body adjusts to breastfeeding. Well here we are at 10 weeks and my letdown is still too much for him. Is there anything I can do to help my little guy?