I need breastfeeding help!

So about a month ago. I was able to produce a lot of supply. Well I was told stress can lower your supply. But was wondering how can increase my supply back up. I'm having a hard time with my baby latching. And I hate to give him formula. Only because I didn't open to give it to him just yet. I want to continue to breast feed. And giving him formula. Makes him a bit constipated. Please help a mommy out.