I'm so deeply sorry that your parents reacted so harshly and so unfairly to you coming out as transgender to them, Eva! Although I can understand that it must be hard for a parent to come to terms with the fact that their child is not happy in the body they were born in, there is absolutely no excuse for the extreme reaction and threats you received from your parents!
As wolfduality said, it'd be good to try and start saving up money just in case (you could also start researching the different types of scholarships, grants, and loans available for undergrad, as well as look into the dorms, meal plans, and work-study programs at whatever college/s you're interested in), but don't give up on your parents just yet! If you don't mind my asking, what has your relationship with your parents been like up until this point? Because most parents, no matter how much they disapproved of their child's choices, wouldn't really do anything to hurt or neglect their child. If your parents have generally been supportive of you up until now and are generally just prone to over reactions like you said, then hopefully they are just shocked and angry and making empty threats to try to push you "back in line" as learningtolive said. And if that's the case, there's a chance that they might begrudgingly come around.
I really hope things turn around and that your parents change their minds! Whatever happens, we're all here for you if you need to talk!