Am I not black?

I'm a multiracial person who's black on their dad's side and white on their mom's. I've never been excluded by my black family members but I feel excluded by people online who say I'm not black enough to claim the label black and I should just say I'm biracial. I've been told I'm black enough to be Black but not black enough to be Black. This has been going on since I was a little kid, who growing up, I wasn't white enough and wasn't black enough. I'm sick to my stomach seeing everything going on in the US right now, to be completely honest, I wish I could support a cause which is dear to my heart with my whole heart, but I'm afraid I'll be excluded. I find solace in being black but I fear I'll be rejected by the community I hold so dear.