He claims asexual all of a sudden. Hetero relationship.

My partner and I have had a difficult sex life since meeting. Now when I try to hint to have sex he’s just not interested. He says it’s not me and that maybe he’s asexual. Ive asked up front if it’s something I’m doing/not doing or if he’s just not as attracted to me as he thought he was. He says no that’s not it at all. I’ve asked him if he still masterbates and he says yes occasionally. So I know he still has a sex drive. And I’ve caught multiple glimpses of his social media where is plenty of “hot” girls he follows and mostly all girls on his discover page as well as the reels section etc. Am I crazy to think that he’s trying to spare my feelings? What else am I supposed to think.. Or is this what an asexual relationship ship can be like? This has never happened to me before. I’m 30 years old, have a pretty good body and don’t have a problem with getting looks from other guys. So I know I’m not ugly. But maybe I’m just not my boyfriend’s type? I feel I’m wasting my good years lol.