I'm depressed

Have you considered attempting to find out what the problem is, from THEIR perspective. I say that, because it's a pretty foregone conclusion that you've already come up with a "reason" that your family doesn't want a relationship with you, but, unless you hear it from them (ALL of them) you're still working off an assumption that could be completely false.

Get some professional help, and maybe try talking to them. You might find that your differences aren't terminal (in any sense of the word).

Family is usually very forgiving.