Write down your feelings, taking time to do so in a clear way not charged with emotion. Explain you love them but cannot continue to live a lie. While you live at home it will be very difficult for you but you can get support by asking child welfare to at least try to talk to your parents. Your doctor could also be involved in talking to your parents if you truly are self harming and contemplating suicide. Your sexuality is your own business, your parents will have to recognize that at some point, maybe not until you have left home. Try your best to get outside help, their are help lines for bi-sexuals, lesbians etc. Get help.
All the best
Chicken little