I think marriage counselling with your husband WITH individual counselling for yourself is the way to go. Not to immediately work on reconciling your differences with him, but with a view to figuring out if you can love him like a wife should love a husband. And find out if you can trust him again. Thing is, there's always the chance that after he's gotten you back, he may return to his old ways.
Is there any track record for figuring out if your husband will return to his old ways? Have you been through serious problems like this previously?
And the other guy in your life....is settling down with him an option? Is the passion from his side equalling yours? Would he make a good step-dad to your son? Do your attitudes about child rearing align?
Edited to add: if you should decide to leave your husband - don't rush in to go live with your ex. Give the new relationship at least a year before making any decisions.
Last edited by basilandthyme; 16-08-13 at 06:03 AM.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.