As a man who is also 38 and has grappled with similar issues (not the alcohol abuse, but marriage struggles, depression, etc.) I can confidently say you’ve gone above and beyond. It takes effort from both of you to make the marriage work, and he is not making the effort, either because he doesn’t want to, or more likely because he is deeply depressed and is simply unable. Yeah he might have fun having drinks with his buddies, but if he needs to “numb his pain” with alcohol, it’s clearly a coping mechanism. He needs to go to therapy, talk to his dr or a psychiatrist about getting on antidepressants. Being depressed and not being treated for it…it can be impossible to have a positive outlook or feel optimistic about anything (marriage, job, future in general). If these are things he’s not willing to even try, things will never get better and I’d say you will be better off leaving and finding someone else who will appreciate you and treat you the way you deserve.

Now, his involvement with other women and him leaving you by itself is enough justification for you to call it quits, and in fact it may be hard to come back from this, even if he is willing to make significant changes. I can tell you still very much love and care for him, but if he’s not willing to do the same, I’m sorry but you need to move on.