I'm sad you feel that way, but I guess I won't change your mind with any arguments I might make.
For myself, I see myself primarily as a human, not a white human, or a male human, or an English human, although they all contribute to my identity. I just don't see those things as of primary importance, and are merely accidents.
You say you are worried that your grandchildren will have no place to live among their "own kind". Being human not enough?
Frankly you sound like a racist.