How to be more positive person towards life and other people? And how to improve other qualities?

Basically my bf broke up with me 1.5 weeks ago and the reason was my negativity.

I am a Pessimist he is and Optimist and it doesn’t work out. He said I was disappointed a lot, looked resentful and sad all the time. He said most of the time I looked like my dog just died. Even his family asked him unbeknownst to me if I’m okay. So I need some tips how to be more positive person and happy person.

So In general I need tips for: - looking happy and content - being positive towards life and others - taking criticism better - taking people more seriously when they tell me their issues - taking more initiative - communicating better and being more charitable towards people I communicate with - thinking positively

Yeah any tips mean a lot to me. I have visit with a psychologist in a week but I wanna start now.

Oh also I am going to church everyday now and it helps me a bit with the breakup, but it doesn’t help with yeah the rest of my pre breakup issues