I broke up like 6 months ago (i called it off), but I still care if he is fine or not. How to overcome this?

I think what you need to do is give up the expectation that you can or should quit thinking about him. So you wonder about him sometimes, so what? When those thoughts come into your head, let them, notice the thoughts, and then let them go and think about something else each time. In other words, stop being hard on yourself about the thoughts you have. If you just accept the thoughts, and then let them go each time you have them, they will eventually diminish, and one day you will realize that you didn't think about him at all the day before.