Supply issues confusing me

So I went from having a huge oversupply to barely having the bare minimum for him and having to supplement with formula. Then i woke up today and my oversupply is back with a vengeance. I'm 5 months PP and haven't gotten my period back either. During this time he also didn't want to nurse at all and didn't like the taste of my milk I guess.

Any ideas on why this happened or how I could prevent it in the future as well??

It was stressful and id6love to avoid it again if possible...