I've had somewhat similar feeling. I'm very sex positive and I like masturbating. I've been feeling like I would like to have sex but in reality I don't have any person I would like to have sex with. Not even celebrities so that's different from you. I can feel arousal when I look at a beautiful person but it's not really connected to wanting to do anything sexual with them. Whenever I fantasize about sex with someone it's just nameless faceless person. When I masturbate I don't think about anyone, it's more like yoga for me, just focusing on the sensations and breathing.
I asked about this on aven and got some helpful response there. The repliers said that libido and sexual attraction are different things. If I feel sexual arousal but don't experience the desire to have sex then asexual fits as a definition for that experience. So nowdays I identify as a sex favorable asexual. It would be nice if I someday meet someone I want to have sex with but it's not my priority so I don't take any steps currently to try to make it happen, like dating.