I’m confused...

I have a high sex drive. My SO use to be the same way. But now we don’t have sex nearly as much as we use to (like 2x a week when it use to be like 5x a week). I know he’s not cheating on me but he regularly watches porn/masturbates. I didn’t mind it till I started getting sex less. It use to be “you never start it” now its “I don’t want to have sex with you if you beg, it’s unattractive” but how else is he supposed to know I want it unless I ask him? (btw I never “beg”. I usually just ask if we can have sex) What am I supposed to do? How can I get more sex out of him? Also why does he think he’s the only one who can decide when we have sex? Why don’t I get a say. I’m lost and sooooo confused.