If you can get the intel so you know what's going on and can control yourself... keep at it. The only reason NOt to do intel is (getting caught may bring divorce, but in your case i doubt it), or the intel makes you so upset you do damage to your marriage.
Have you found a FT that can talk with him? He sounds like he WANTS constructive advice. He sounds like he's drowing and hopeless... again not the state someone should be in when they choose to get romantically involved, but we both know that's not going to end well anyhow... its just a matter of time before that crashes and burns... they always do. If you can find him a friend or FT to talk to then DO that.
Your H needs to understand his feelings of HOPELESNESS right now are AFFECTING his confidence in his marriage.
If you feel hopeful, your marriage looks good, if you feel hopeless and depressed, your marriage will look miserable. He needs to know that he CAN'T decide the fate of his family based on his MOOD... he needs MORE than a MOOD to motivate divorce.
If you can get a marriage friendly friend or family member to TELL him this, that's best. Try to get your info to him THROUGH someone ELSE if you can.
Maybe asking him for commitment isn't best. He needs to know his affair is the obstacle to progress.. but it CAN'T come from you.. he must be told this by a good friend he trusts. Any idea who can talk to him?