My sister has betrayed me and now my father has washed his hands of me?

My eldest sister has always been jealous of me. She thinks I have had eveything fall in my lap when I've worked really hard to get a house, run a business etc. I'm in a stable relationship and she always came to us for advice. Now she has told blatent lies about comments I've supposedly made about his new partner. She now detests me. Dad has disowned me. I get on with my mum, my sister has a rocky relationship with her. She is jealous of that. What hurts is that she got me ousted on Dad's side and he hasn't got the to stick up for me, he knows me better than that and now It hurts like hell that i can't do a thing. Sticking up for myself makes me look desperate. What should I do? leaving things unspoken may make me look guilty to. I can't sleep at night. I just want to prove she is a vindictive cow after revenge to make her look better. I supported dad when his marriage failed and he was ill with cancer, after he chose to ignore us for 8 years. (My parents divcorced when i was 3)