The very best thing you can do is seek help outside the normal guidelines. Speak to a Dr, Health Department, other relatives that may help (Aunts/Uncles).
The very best thing you can do is try again and again to get your own parents on board with what is going on. The best defense is a good offense in this case. An unbeatable confrontation on the pros/cons on the topic and so on.
I am not stating that fighting is the way as that will never work, but a heart to heart. You may have to give to receive in the return, but it'll be better than nothing.