Hey, I was on this site, long ago, as Auroramarianna, but deleted my account. However, when I saw your post I had to register and comment to help you. Because I identify sososo much with your story.
First, a suicide attempt is not a smart idea at all. I also went through depression, and my parents, being as unsupportive as they are, actually took my gender dysphoria less serious. Suicide attempt will just give them a excuse to make you look crazy, delusional and out of control. It sucks because if they were supportive, they would try to understand and accept it and not condemn you for being in pain. Really, I agree with almost everyone here, don't do it, you'll do more harm than good, could backfire totally.
Your parents really sound like mine. Completely out of touch with reality, and not aware they have a daughter and not a son. If you are like me, then you were always femme and if you told them, then there's no reason for them to keep being this way. And although maybe you wish your parents would be different, you may have to let go of that expectation, just like they have to let of the expectation that you will be their "son", because you never were and never will be.
Time to start changing. Start working. Save, save, save, save every penny you can for your transition. And if you can move out, preferably go living with someone you trust, or someone who is trans-friendly. A roommate is a great way to have less expenses and divide the room's rent. Do not expect your parents to change. They might in future of they want to be a part of your life and see you are doing well without them...or they might become resentful and angry that you are being sucessful at something they never wished for you. If the latter is the case, then too bad for them, it's their loss and shows they are hateful people.
I truly wish I could say help you more and guarantee that oh yes! your parents willl be soooo accepting. But giving that advice wouldn't be real. Truth is if they have been this unaccepting till now, you can't count on them for transition, they might change after they see how happy you are or they might not. Whichever the case, their attitude is not your fault. I'm actually in the same situation. I started working, paid for my HRT, started passing into 1 month and half of HRT (I was feminine looking before and have a high voice naturally), and my parents still treat me by my old name and pronouns haven't changed. They also had threatened to put me out in the street with no money if I didn't go to college, which I didn't want to because I haven't changed my name. And I haven't been going because it was too dreadful...I just work, work, work and had to change jobs. They still do not know. I do not recommend hiding things from them, but I did for my survival. I am getting ready for every outcome and so should you.
If they refuse to pay for your education as a girl, then they were not worried about you in the first place. My parents also didn't want me to go as girl. You now have the ability to support yourself. So, change your name, find a job, and start attending classes. I know it seems like many things but you can do it. Believe in yourself, even when others don't. Hell, I am glad to have started this journey, even without my parents' support, I have come so far.
best wishes and good luck