You want to be "human"? Well guess what, honey! You ARE! And that's all that's really important.
I don't buy into the whole "race" thing, personally. Because 1) what does it matter?, 2) very few of us are actually one single race, and 3) it's a social construct use to categorize and label people.
Ethnicity can be important, in that it can be useful for medical purposes (some ethnicities are more prone to certain diseases, etc). And certainly ethnicity (and the corresponding culture of that ethnic origin) can be something one honors as part of their heritage, which can be a beautiful thing.
But beyond that, it's never really clicked with me why it's so important to people.
So try not to let it bother you too much. At your age it's quite common to not want to feel "different" - but 1) you're not, and 2) different is good, anyhow!
And if people want to label you - black, mixed, "not mixed", whatever - that's their issue. Don't let it be yours! Certainly none of those labels are bad things, anyhow, so again - their issues, not yours.
Hopefully you'll come to a point where you can say "well, my dad is this and this, and my mom is this and this", and it's no more than a factual, interesting fact about your genealogy/heritage! Same way I say "my dad is Italian, Cherokee, and British, and my mom is British and Swiss" - because its not different than saying african, Chinese, etc - even if some people see you and treat you as if it's different. Again - THEIR issue!
I have two friends who are "mixed" - one has a black father and a white mother, one has a black father and a Hispanic mother. Both have said they have felt like they weren't accepted or didn't belong in either "catagory". I have a student who is caucasian and yet people assume she's "mixed", and she even feels some of that. I think it's a common issue for people of apparent mixed race. Again I've never understood why it matters so much to people, or how someone could have the nerve to say "you aren't black/mixed/Hispanic/white enough". What does that even mean???
Sorry for the long post - lol! But I hope maybe it helped in some way?
Just be the PERSON that you are, not the "race". Anyone who can't accept that - THEIR PROBLEM!!