Dear Sassy,
I know exactly how you feel. I’ve been in that situation and found my own way out of it. Everybody has a different path and so I will share with you what helped me.
I remeber how my last ex made me feel. It was amazing. A few weeks after we had broken up I still had feelings for her and I could not shake them off. My heart and my brain disagreed with each other. What helped me was a moment of peace and silence. I stood there by myself and let go of every thought. No, I did not follow my thoughts nor did I follow my heart. I dismissed them both. Only when they are no longer a factor can you hear the soft voice of your intuition. Odd though it may seem I recommend finding that soothing voice of your own intuition and following the advice it gives you, for better or worse. Only then will you have no regrets.