The fact that you can make this honest evaluation of yourself shows you have great potential to grow into more the kind of person you want to be.

You are probably your own best adviser, but you forget your own advice when you get riled. ( I'm the same way.) Start writing your insights down in a journal. Then skim through it often to remind yourself of what you want to be mindful of.

Make it a point to apologize to people when you realize you've been off-putting in your manner. You'll be surprised at how well that goes over. It will help you feel warmer toward others.