Best of wishes to you.
I remember when my ex-fiancee of 5+ years and I broke up. We were dating since our mid-teens. I felt like Elmer Fudd had finally caught and shot me in the chest. Had a lot of trouble sleeping for a week or so. Took a few months to feel like myself again.
After a year, I dated another girl for 1.5 years. I was so glad I didn't marry my ex-fiancee! This girl was great, but again, we broke up and it was hard, but not nearly as hard as before.
I'm currently dating another girl now, for about 9 months. I'm so glad my ex-girlfriend and I broke up! I like this new girl a lot.
Just remember that happiness is something you bring with you. It's something you share with other people. I am happy being single or in a relationship.