Why do I mistrust everyone so much?

Whenever someone tries to get close to me in terms of loving relationships I always push them away.I'm a 26 year old guy and have been cheated on by an ex girlfriend.Now I seem to hate not only promiscuous women but people in general and I'm frightened that the more time goes on,the colder and more distant I will get.Will this destroy me eventually if I dont find a way to turn my trust around?