How can I save my marriage?

Obviously you are not in a very good situation. First off, the boyfriend thing is completely disrespectful. Secondly, one cannot make/convince/ coerce another person to accept or love him/her. You tried counseling & she is still unhappy. If you have tried your best to improve things & she is still unhappy, then I am sorry, but you may be best off divorcing her & moving on to a happier, healthier relationship. Best of luck to you.