My H did have an online EA about 8 or 9 years ago...when I found out I was so deeply hurt and betrayed (didn't think anything could hurt more....found out PA could)....anyways....I did what your H is doing...it was a way to escape...and also a way to avoid dealing with my depression!...I really think your H is depressed and trying to escape it because he doesn't understand all the feelings going on right now...
Might be time for an intervention with his doctor...or a counselor...
I give you credit for giving him space...but I think there is a time when you have to look at the big picture and this is one of them...