Formula Advice Plz!!

FTM & have a question about my baby(4wks old) & FF. I wanted to exclusively BF my daughter but 2 weeks PP , my supply stopped coming in out of no where. (Was BF & pumping, & still dried up!😔) so we had her on Similac Pro-Advance, it made her really fussy, gassy, & constipated. We then switched to Similac Pro-Sensitive , still gassy , fussy, & constipated, but now she's starting to spit-up frequently (watery w/ white chunks) , my SO thinks she might have Reflux because of the chunks (formula not fully digested) , but she doesn't cry when spitting up like they say if babies have reflux......so my question is.....what formulas were successful for you mommies? That helped babies not be fussy, gassy, constipated & not spit up?

Thank you for any advice or suggestions....they are greatly appreciated! ☺