what is this feeling?

 I know he's with someone tonight and I don't know who and I doesn't really matter. I have that feeling in my chest.

The last time I felt it was when my ex of 13 years and I broke up. when I knew he was with someone else who he preferred over me. 

people experience this all the time. it's just part of living. You can't always be the one who gets picked. You won't always be the one who's loved. 

this horrible feeling that is hurting my entire body will go away in time. just like it did with my ex. someday in the future if I see him I will look at him and I will wonder what I ever found attractive in the first place. 

but tonight it's just going to hurt and I must remember that he is taking pleasure in someone else and I am not on his mind and that makes him unworthy of my attention

and this too shall pass.