I don't know your current habits, but I can try.

Impatience can make us angry and rude. Learning to slow down and appreciate each moment makes it easier to be patient.

It also helps to remember that other people exist even when you're not around them. If you can learn that, compassion comes easier. I could judge you for not being kind and compassionate enough, but I don't know how mean you really are, or why you feel like you need to change. Those are things I think about when I'm forgiving myself for mistakes so why shouldn't I do the same for you?