Have you not dated anyone else in the meantime? Sometimes its just easier to fall back on the last person you were with if there is nothing else there. Sounds like your self worth needs some building up. You deserve better than someone who cheated on you. Now that I'm with a great guy I see things so clearly in my past relationships. You can only polish a turd so much. He'll always be a turd.
So, so you think you can tell Heaven from Hell,
blue skies from pain.
Can you tell a green field from a cold steel rail?
A smile from a veil?
Do you think you can tell?
And did they get you to trade your heroes for ghosts?
Hot ashes for trees?
Hot air for a cool breeze?
Cold comfort for change?
And did you exchange a walk on part in the war for a lead role in a cage?