Ever notice that if you rest the guitar on your hip bone (pelvic bone?) and play the A string you can really feel the resonance? That was a pleasant discovery when I was home alone one evening practicing.
Have you tried playing the mental game more? Movies, books, poetry, or music that stir the blood? I'm not post-op so I could be completely full of it, but I find that the more I work at paying attention to things that turn me on even a little bit, the stronger the effect becomes over time, until one day the wind blows and it's like..oh, hi

Or if I just ignore it and get buried in life's misfortunes then I may as well be asexual.
Just my experience, maybe it helps, maybe you're way past that. Either way, I hope everyone gets it figured out...life seems much more magical with it than without it, ifyouknowhatimean

Addendum - perhaps I should add, being turned on doesn't mean you need to climax, just enjoy it. No pressure.