nikita Hi Nikita, am so sorry to hear that. If you are really sure that you have tried to convince them and have done your best, I, in your case, after trying my 101% would find a way to get a job in a different city and start the journey of transitioning on my own. I don't want to encourage you to contradict your parents, but when you have to do something, you simply have to have the courage to isolate yourself and follow your dreams.
Wounds heal with time. They will be angry at you initially, but with time will accept it.
BTW have you tried to put on shows on TV that address these types of issues? I know for a fact that as human beings, we tend to not give time to things we don't want to believe, but once involuntarily, we happen to see the same thing happening to others, we start to accept these facts, even if we were against them. Don't just ask your parents to listen to you, turn on a show about these issues on TV/DVD/Youtube during the time all watch TV. Do this as many times as possible. Can't explain how these things are important, but they enter into the subconscious mind of people watching it, and with them they are more accepting by looking at positive aspects of people undergoing the transition.
My Suggestion - If nothing helps, get a job in a different city, visit a psychiatrist, start hormones, plan your surgery, and later when you have to, disclose the fact to your parents. Be prepared, just in case, they don't accept you. After a thunderstorm, there is always a way for recuperation.