If you have the diagnosis (you can always get copies from that doctor), they may be able to prescribe you
metformin. The generic
cost me something like $1.75 a month (my
insurance paid if it was OVER $10, so it was not because of my insurance that it was so cheap).
Even a regular clinic for general health could probably help you.
Perhaps you can even call the doctor who diagnosed you and get them to prescribe you with something? That would probably be the best place to start.