I'm glad that you have a supportive family! And honestly, I'm a little jealous that you never experienced self-hate with your sexuality. I remember trying to force myself to be straight when I was trying to accept my sexuality, and it spiralled down into some sick Pavlovian methods that I'd force myself through every time I felt an attraction to someone of the same sex. I'll spare you the details, but I am not proud of the things I would do out of sheer desperation to be 'fixed'. It makes me relieved to see people like you have a strong support system to fall back onto though, because even if your career tanks, at least you'll always have your loved ones to rely upon.
I also know how sensitive sexuality can be in with careers. Personally, I'm at a point in my life where I can be open with my sexuality anywhere and not care about the consequences. It took me a long time to get to this point and maybe it will damage my career later on, because bigots will always exist in whatever industry we work in. But one of the reasons I don't care is because: 1. The LGBT is becoming more accepted these days, so I feel more confident in expressing my bisexuality. 2. If I do end up losing my career over my sexuality, then I can always find another job somewhere else.
I recognise that we have different experiences though, and I get why you'd want to stay safe. Honestly, it's a good career move. If you do plan on coming out publicly someday, my advice would be to keep supporting the LGBT community as a 'straight' activist, and then be upfront about your bisexuality once everyone's used to seeing you in the LGBT scene. Maybe not the best advice ever, but it's the best I can think of.
Good luck, man. And one last note, if you really do feel guilty about hiding this part of yourself: don't. Easier said than done but honestly, you don't owe anyone jack shit, much less this kind of knowledge. It'd be cool to have such a famous LGBT role model, sure, but you got to care for yourself first.