Get your head together and get yourself a new love, but even more importantly, learn to love yourself. I would suggest that you not jump ship yet. People do not usually have affairs because they are horny. They have affairs because something is wrong in the relationship or marriage. I implore you to try to find out why she had the affair and make an attempt to work it out.
Statistics show that seven out of ten couples usually encounter a marital infidelity.
It is usually tougher for the man to accept and work through their wife cheating. That is because we are so darn macho. Three or four years down the line I don't want you to be despondent because you have had the experience that you didn't do everything that you could do to save the marriage. Right now you are still in shock and therefore should not make any rash decisions about getting out. Seek therapy and try to work through it.