I'm thinking of no longer wanting to emotionally invest in someone I'm not close with anymore and cutting them off
Why do you feel you should do that?
I find it really stressful.
I'm sorry you feel the need to do that, but I think you're justified in cutting them off.  You have the right not to be around someone who stresses you out all the time.
It's not like I'm not feeling anything but there are other things I want to focus on right now.
Hey it is ok to take some time and get in a good mental space for your self. Sometimes we just need to focus on what we find important in life.