Honestly respirators aren't great to wear long term, even the best build up heat and moisture. You'd probably be better off with a portable spray booth like this. Additionally it's a one time purchase vs constantly buying filters.

AW Portable Airbrush Paint Spray Booth Kit w/Turn Table Extension Hose Powerful Fan for Toy Parts Model https://smile.amazon.com/dp/B00Y83Y1C8/ref=cm_sw_r_cp_apa_i_MYxuEbTHBQ0HH

Just out of curiosity, what paints are you using? I've never noticed much vapor with acrylic paint, maybe try a different brand and see if they effect you less.