I think he's asexual

My husband and I have been together for a year and a half. When we first started talking he told me he wasnt into sex, and I figured he meant until he was married. After we first had sex, we had it often but it quickly dwindled down to maybe 3 times a month. He is always asking me why I want sex more often than we have it. I can try so hard to make sexual advances to him. I'm more than willing to try new things with him. I've tried talking to him to find out what his deal is about not ever wanting to have sex but he always says he's not into sex and could do better things with his time than have sex with me. He says he loves me, but doesn't want to have sex. It really puts me in a weird position because I enjoy having sex with him when we do, and I'd do it more often if he were willing.

I'm bisexual but I've never dated or been with a woman before. I keep having urges that seem to get stronger about being with a woman. I love my husband, and I want to be with him, but I also feel like if this is how he feels about sex then I should experiment with women so I can feel satisfied as far as sex goes. The thing is we've talked about it lightly but he's against it and thinks its considered cheating. Has anyone else dealt with this? How should I deal with it? I feel so confused