My dad...:/

I've been thinking a lot about my dad and when to come out to him or if I even want to. He barely talks to me anymore. I only exist every few weeks or months when he decides to call me which is not easy to deal with because when I was younger I was daddy's little girl and was always with him. He knows I've dated girls and I told him I was bi when I was 16 but I'm pretty sure he thinks me liking girls is a phase. Him and my stepmom always tell me how much I'm like my cousin (minus the drug addiction) and how I used to want to be like her when we were younger so I'm pretty sure they think I've dated girls because my cousin did when she was younger and that I'll "grow out of it" like she did. He already looks down on me and says I'm an embarrassment so I feel like if I come out to him it'll just make things even worse than they already are. I mean he plans on moving out of state soon and I know that once he does that I probably won't ever see him again. Part of me does want to come out to him and show him how happy I am and how I found someone I want to be with for the rest of my life (he's already met my girlfriend but doesn't know she's my girlfriend and he likes her). But I feel like he'll reject me even more than he already is. Should I even bother coming out to him or just let it go and hold onto what little is left of the relationship I have with him while I still have it?