Contra Cyan & Alicorn, I am inclined to go with PhilGoetz and "punt it off to your moral system, or your expected-value computations."

Trying to change your homosexual desires will probably fail and create a lot of collatoral damage. I would guess that trying to change your desire for heroin is somewhat more likely to succeed, though I'm willing to consider the argument that heroin addicts should accept their addiction but attempt to minimize its harmful side effects.