I'm hurting 😞

Me and my ex boyfriend broke up like 4 months ago. I got a new person to be with and I'm happy.. But I have sutle moments of missing my ex 😥 I recently looked at his Facebook and he's dating a new person. I don't know how to feel! I don't want to make my new dude suspect that I'm messing around because I'M NOT! I just.. To be honest I don't know how I feel.  I just want to be alone, and cry.