You could blame your parents for not respectively picking a partner of a different skin color since your own existence is their doing, essentially. So then why blame yourself when it's your parents' fault?
/sarcasm
Come now, do you even know what the word "guilt" means? In this context, it's about the feeling of having done something wrong. What did you do to be born a white heterosexual male? Heck, what did you do to be born at all? Though I have to say that if I wanted to torture someone long after they've left the torture chamber, I would convince them to feel guilty of something they have absolutely no control over. It does raise the question whether or not whoever convinced you had this nefarious plot to make you feel sour for the rest of your life. It does seem to be working.
Implying random people care about your existence any more than you seem to care about your own. Funny. But hey, as long as it convinces you that your existence is more relevant than it actually is. Doesn't that make you feel special even if in a morbid way?
Tell me something. What would you do if a black person came out and proclaimed to hate their skin color? Be honest now.
Let me guess, without that guilt, you'd be empty-handed, wouldn't you? Being all guilty sucks but at least it isn't nihilism. Guilt gives you this illusion of responsibility, this illusion that your life has any meaning whatsoever, making you see yourself as more significant than you actually are. All this talk about being white, pansexual, non-binary... Have you really nothing else going for you?
The judges for mental gymnastics are in:
People who tell you that don't know what they're talking about. Racism is about judging a person by only their race -- individuality be damned. It won't matter how good a person you are, you'll always be evil because you're white. On the other hand, it also won't matter how malevolent a psychopath you are who cannot refrain from skinning kittens alive to save your life, you'll always be a victim in need of compassion because you're [insert oppressed race here]. Racism cuts both ways, you see.
If I wanted to make you suffer more, all I would need to do is entrench your biases and watch as the avoidable suffering that comes with your warped ideas makes you hate life with ever-increasing intensity.