The heart wants what it wants, but the man so called is reasonable, that lives not only instincts, but also the mind. Try to inspire myself: such a situation was simply humiliating for you. Even now not like the old days, and the word "lover" is no longer friendly universal condemnation.
Think about it: you are a grown, independent woman, you have something to love. Because otherwise this man would not pay attention to you. So really you will not be able to start a family with another man, become the lawful wife, not mistress?
Try to increase self-esteem. Analyze their behavior, consider what adjustments it should make to be interesting and attractive to the opposite sex. Maybe you should cardinally change the image: make a new original hairstyle, update your wardrobe.
There are quite harsh, but effective way to forget a man: to be very angry with a former lover. He says, well settled, lived with two women at once. Convince yourself: if he loved you truly, would have found the strength and courage to leave my wife. Again broke up, then, never loved you and only used.
Try to convince myself of the correctness of the decision and this argument every day with a married man, diminishing your chance to arrange his personal life. Because over the years, alas, younger and more beautiful one becomes. So do not mourn for the past, and start looking for someone who will love you truly, will offer his hand and heart. It's real.
Attend parties, theatrical performances, concerts, go to bars where probably will meet lots of men. Sign up on Dating sites.
To escape from painful thoughts, find yourself some interesting hobby. Try to go to a resort, certainly, there men you are interested.
Short, non-binding novel that will bring you confidence in your attractiveness and feminine charm will help you to dismiss the former's unrequited love. And who knows, maybe it will develop into something more serious.