i recently came out to my dad and that means my stepmom knows, and everything is oky. but being bisexual to the rest of my family is gonna be horrible. i dont know how to tell them
I'm sure you'll be fine, just try not to panic too much. Do you know if your dad or stepmom would be willing to help you talk to the rest of your family? That might help.
I'm glad your dad and stepmom were cool with it. However things go with the rest of your family, having them stand behind you and support you will be very helpful. I think Tiontole gave some great advice. Maybe they can help spread the word a little, if you're comfortable with that, and if they're willing.
I agree with the posts above. However, remember that you should only come out when you´re fully ready. Take your time, don´t rush it if you don´t want to.