the biggest apology due is the one you owe to your wife and son YUK, not so much in words but by thoughts & actions from now on. as I recall you were supposedly gaga in love with her when you met and made lifelong commitments to her including the birth of your son.
imagine the hurt you'd feel if she were playing the same game on you. work harder at making things right and if one day both of you feel the same bad way about things and not being able to remedy them then all 3 of you guys can look for the best way out.