How'd you get a piano if music is so discouraged that no piano teachers can be found? I'd start by asking around for a teacher where you bought the piano/keyboard.
I quoted this from the Wikipedia article on "music in Saudia Arabia":
Music, however, is considered "sinful" by some Muslims. This is based, in part, on certain ahadith which speak negatively of non-percussion musical instruments and the idea that music and art are distractions from God.
You should tell the authorities that the piano is a percussion instrument;)
Seriously though, it seems like if you're in a big enough city to have a medical school, there should be areas liberal enough that you could find someone who could give you instruction in playing the piano if you ask around enough. You can certainly learn to play without a teacher, and there are a few famous examples of great pianists who were autodidacts, such as Leopold Godowsky, but they're exceptional.