I need some help/insight

I had a super hard time breastfeeding my son. I made enough for him and nothing more; he was always tiny too :/ (5-10th %tile). This time with my daughter I was ecstatic because I was over producing! I’d feed her and pump 3 times a day and save 12-15 oz a day. Then around 6 1/2 weeks my milk drastically dropped. No change in diet, pumping schedule, feeding baby.. it literally happened overnight. One day I pumped an extra 18.5oz and the next I was barely getting anything. I thought it might have something to do with going to the zoo. It was 90 degrees and I felt lightheaded and had a terrible headache and muscle cramps for a few days... maybe I got dehydrated. Well it’s been a week now and it’s not getting any better with lots of fluids and increasing pumping frequencies. I’m at a loss and getting frustrated. She used to get up 2-3 times at night and now it’s 5-6 😔

The only other thing I can think of is my baby girl has finally stopped projectile vomiting every day. It’s now only every once in a while. She still spits up a lot but doesn’t vomit like she used to (usually 2-5 times a day). But with that I’d think I’d be getting more not less.