How do I increase evening supply?

I'm exclusively breastfeeding my 6 week old and my supply is pretty wonky. I seem to have an oversupply in the morning, but by evening I feel almost empty. When I feed my little guy in the morning he will drink from one breast while I use the haaka on the other (getting 4 oz). In the evening he will drink for quite a bit on each breast and sometimes still seems hungry.

My son is gaining weight and continues to follow the same eating pattern - eating every 1.5 hrs, sometimes stretching to 2-3hrs if he's sleeping. I have but started pumping yet, but I have one waiting.

What can I do to increase my evening supply without engorging myself in the morning??