Positivity is something I struggle with on a daily basis. It's especially hard on a rainy Monday morning like this.
Negative thoughts and negativity are absolutely contagious as you've stated. I quit reading the news years ago because all it did was make me angry and depressed about the state of the world. I feel like I have enough things in my own life that drag me into the negative thinking feedback loop.
Training my mind to be positive is something I've worked at for a long time but haven't made much progress on. But at least I'm admitting to my negative outlook which is one of the first steps in changing it.