You wish you could be nice to everyone. The reality is you will face people who annoy you and irritate you. Even being around them can make you feel anxious and negative. It does not have to be this way always. You can train your brain to think differently, change the way you relate to them.
I need to acknowledge anger. When angry feel what part of the body it is in. Remind yourself that there is space to react. Be thoughtful about your reaction.