Ran into ex-gf with new guy

Ran into my ex-gf today at gym and saw her with what I believe is her new guy (just had that feeling due to the expression on her face.) Our break up was mutual and I was absolutely ok with our break up until today. We have kept in touch because we together almost two years and ended things on a good note. Ive been doing great since our breakup and doing well being single again. Seeing her with him crushed me though and made me think I had made a mistake. Ive had breakups before and run into exes with their new significant others and it never hit me like this. My stomach was in knots as i was trying to be confident and brave but it was too much so I left. Maybe I didnt want to see her laughing with him the way we did or trying things that was I apprehensive about doing (certain type of rock climbing, not anything crazy or weird.) as I was leaving I received a call from my mom that my grandfather was rushed to the hospital with pneumonia (has emphysema and COPD already) and probably will not make it. This news made it even worse since I didnt have her to help me through it. Shes a great person and we shared many great times but certain pieces of personalities did not mesh. I felt (and was told by friends) that she was controlling and saw me changing in ways they didnt think were me. On the other hand, she truly made me a better person in some aspects of my life.

I know (hope) this will pass but Ive never felt like this before. To top all of this off, I will be sitting next to her at a concert on Friday.