Im not transmasc, but I can tell you, yes, HRT effects both libido, and sexual desires the longer you are on it. It's quite the ride, but a long one unfortunately. It does get better though.

The real change happens within yourself, and your lived experiences. I think you are having more of a hard time with understanding how to perform as a man, because you haven't lived it yet. I constantly have this feeling within myself, that I'm not woman enough, and that I just dont know if it's what a cis female feels (in any given moment). My gf is also a transwoman, and shes often has a few more residual Male tendencies than I, so it helps me feel like the feminine one... but it still doesnt give me the "oh this is what it's really like being female" feeling. It's such a diluted mindset, but if you can somehow learn and try stereotypical (ew) Male tendencies, it might change your feeling/viewpoint, and in turn, your sex life.

If I'm off on that, sorry. It just sounds like my situation. If it's purely a genital thing, I have a story for that too. Lol