I totally agree with this. I will give you a very wise saying:
I you love (truly) something or someone, set it (he, she) free.
If it was yours, it(he, she) will return to you.
If not it (he, she) was never yours.

I went through this exact problem and I didn't think I could live past the pain it caused me. But I did and the one I loved married someone else and got divorced. He came back to look for me only problem is that when he came back I no longer saw in him what I thought I once saw. We stayed friends, but I would never give him my heart again.

Hope this helps. Best Wishes.