People hear about other people's reputations. If Mr. or Ms. Right is attracted to you but sees you out with someone who's known to be a sleazeball or an airhead or a loser, he or she is going to conclude that that's the kind of person you're always attracted to. The only answer is to bite the bullet. Get Mr. or Ms. Wrong out of your life, so you can be happy and attract a really nice person. It's better to fight being a little lonely than to miss the right person when he or she comes along.
Cold turkey is the best way to get out of a relationship.
You'll find several articles which will help you in this section of my Library.