I'm really sorry your parents have been like this. My son came out as bi about a year ago. He is still the lovely funny person I adore, and it changes nothing.
I had had an inkling for some time that he was either bi or gay, so wasn't surprised when he told me, but was surprised by his evident relief that we still have his back...it should have been obvious, or so I thought!
How old are your parents?
When you have kids you trolly along assuming that they are straight, until you see indications to the contrary. Your Mum may therefore take some time to readjust her world view. We haven't told my Mum that ds is bi, at his request, as she would not cope well with it, and would offer to pray for him, whereas he just wants a hug.
I don't know how old you are, but if you are under 16, then your parents may think this a phase, as opposed to your orientation, and imagine that being heavy handed will make you think twice. Ds was 19, and in his first year at uni when he told me, and I will be as supportive as he requires. It's just a facet of who he is, as opposed to the whole of his being.
Good luck, and hugs. Please remember that if your parents had no inkling this was coming, it will be hard for them to readjust, and their initial reaction may improve with time. You are still you!