32 here, in the same boat. I haven't exactly lost interest in sex, but I have more or less lost interest in the idea of having actual sex, if that makes sense. At this point if an actual girl showed interest in me I'm not sure I'd even know what to do about it or even be especially inclined to bother trying, because I basically have no idea how to have that kind of relationship with someone. Plus, the idea of actually having another person sleeping in my bed with me just weirds me right the fuck out. I don't care if people want to come over to my apartment and sit on my couch and watch TV with me or something, but my bedroom is sort of my private space, and the idea of another person actually being in there with me for any significant amount of time makes me very uncomfortable. Plus, I never found 3D women to be hugely appealing in the first place, and women the same age as me look less and less appealing each year. Something tells me the problem is only going to get worse as time progresses. So I have more or less concluded that sex for me is in the same category as climbing Mt. Everest or something: it's something I could probably do if I had enough desire and motivation to seriously undertake it, but every time I start to take all of the practical considerations for such an undertaking into account, I find that the desire and motivation doesn't really exist for me. Fapping to 2D loli is probably going to be it for me, unless I decide to hire a prostitute or something, which doesn't really appeal to me either.
Also, agreed that Rika is cute, although I always preferred Satoko.