Hi op
My major relationship ended after 4 years when I was 25. We were going to live together, get married, live happily ever after etc.
When he ended it out of the blue I was in a world I have never been in. People kept telling me "one day you'll find someone else" and I couldn't believe it. I physically threw up when I passed his turning on the motorway. I had a mini breakdown in front of a (luckily very understanding) policeman in the station when I heard his train stop announced. It was crazy
Then I did a year of crying, a year of declaring I'd be a spinster, a year of something I'm ashamed to admit, and then, last year, I fell head over heels in love with someone I never would have expected to fall for.
It took me by complete surprise- if you'd asked me my "tick list" of things I always looked for, this guy ticked nothing. But I love him more than anyone I have ever loved, and he is my future.
I never believed I would get to a place where not only the pain didn't crucify me, but that I could agree it was the right decision we broke up
You will get there. Don't force yourself. Don't go dating if you don't want to. Don't fret too much that it won't happen. Kick, scream, cry, sulk as much as you want to.
Then, one day, it will just happen. I promise you it will
And when it does, look up your old threads, come back to this one, and tell us just how happy you are 
Sending you all the love and hugs op