not sexually attracted to my partner?

hi, me and my partner both are 16, we’ve been together 3 years with some short breaks from when they left me. they are assigned female at birth and are nonbinary. I’ve always thought of myself as bisexual as I’ve had crushes on both guys and girls. The thing is I’m only attracted to masculine girls and I’m not attracted to their body’s. I’ve only been with my partner as they are my first love. I don’t really enjoy doing sexual things to them, it makes me very uncomfortable although I like them doing sexual things to me. I’ve never been attracted to my partners body, and that has nothing to do with them I don’t think, they have a very nice body I’m just not sexually attracted to it and it makes me uncomfortable seeing them naked or doing something sexual to them. I’m not sure if this changes my sexuality or not, im not sure how I feel about a guys body in a sexual way either as I’ve never been with a guy. I really love my partner and I don’t want to leave them but I don’t know if it’s right to stay either. please give me ideas on what to do. I’m young I know but I feel like a shitty person.