I keep having dreams of disembering white supremacists and dancing with their heads
Why do you think you're having violent dreams?
In my mind, it's poetic justice. They hate gay people and I'm a proud gay man.
Experiencing violent thoughts about a group of people who want to harm you while you are awake is understandable. As long as you don't seek out any actions in real life or are having trouble controlling your thoughts it is okay. Otherwise, consider talking to an expert so you can go back to having more pleasant dreams.
I do have some doubts about killing those guys so I don't know what's going to happen.
Then you should speak to a mental health professional. I think you just need an outlet for your thoughts. It would destroy your life if you pursued them.