PP PERIOD

At 6 months and 2 days pp my period decided to come back :(

I breast feed and lately my supply has dipped and I had to get formula so I could pump enough again. I had just gotten over a yeast infection too and then woke up to a huge surprise. Is there anything I can do to keep my supply up? Will my period keep affecting it? Will my period be regular? I am kind of sad to be honest.