What should I do if I'm allegedly being a douchebag to dad?
Who is accusing you of being one towards your dad?
My girlfriend of the time actually accused me of it.
I'm sorry you are feeling that way. If you don't think that is the truth, you should probably talk to your girlfriend about it. It's understandable to be upset when you did nothing wrong.
It's fine. I'm an arrogant prick anyway. That's the way I am.
If you notice your tendency to be arrogant towards others, you have the opportunity to work on that and treat people better.