Most Helpful Guy
Even though he was a "asshole" he was still part of your life. You'll still miss the good even if you wanted the bad gone. Just remember your choice and why you made it. You'll be happier in the long run. try doing some fun stuff to keep your mind off it.
Most Helpful Girl
This just happened today, don't worry. Being sad is normal, feeling like you lost something is natural. What's not right is staying in a relationship and suffer while you wonder, every single day. It's preferable to hurt some days now that it's over, than to suffer the entire relationship, feeling like you're about to lose him anytime.
Mourning a relationship is expected. It won't last forever and soon you'll be sleeping in peace. don't worry girl :)