That is a very difficult situation. I'm sorry that you are going through it. Don't give up! Don't give up on hope for the future. Stay strong and true to the man that you are.
I don't know your parents or your whole story, but most parents genuinely want good lives for their kids. Maybe they let you do your thing for all these years, but now for some reason they're thinking that it's time for you to 'grow up and be normal,' and they can't imagine a safe and happy life for you as a trans guy. Like Felix said, maybe an outside authority could help them to see that this is not a phase, you are not crazy, you can't possibly choose to stop being trans, and you can have a good future as a trans guy.