Kid frustrations

I know that parents have a profound impact on their kids' lives. I know that my parents had a profound impact on my life.  That's just the way it works, whether parents are fully involved, somewhat involved, physically present and emotionally distant, or just plain gone.  I didn't recognize how truly disfunctional my family was (is) until I was closing in on 40 years old.  My parents were both home; Mom actually worked from home (she ran a daycare).  Dad came home every night and went straight to his workshop, but he was home.  Everything was so peaceful, no anger, no hurt feelings, no drug abuse or alcoholism, no sleeping around, no real money problems.  There was the chaos of a daycare, but that's a different type of chaos.  I never learned how to face conflict.  I never learned that it's okay to be less than perfect.  I never learned that it's okay to try new things. (I was so nervous asking my mom if I could join the track team in middle school.  It took me a week to work up the nerve.)  I never learned that it's okay to not be good at something.  Everyone's happy.  My long-suffering husband wound up married to a passive-aggressive wall builder who cheated on him (that'd be me).
Now, our sons are 13 and 16.  They are both plenty old enought to remember all hell breaking loose when my Husband found out I was having an affair.  That's after I spent the entire summer ignoring them to have the affair.  Our oldest, when talking about his GPA, said "Well, the first two years of high school weren't exactly stable."  Ouch.  [The affair was the summer before he started high school.  In the early spring of his freshman year, we moved to Europe.]  He seems to be recovering pretty well, although I still have my concerns (especially since he's going on 6 months with his first girl friend).  The younger one is not doing so well.  He's missing multiple assignments in every class (excpet art).  He hasn't made any new friends since we moved.  He is lonely and depressed (Depressed? We haven't established.) We had a good weekend.  We finally met another family in our village who are also Americans and their oldest is close enough in age that they can get together on their own.
I am a member of another website specifically related to Infidelity.  There are so many stories about FOO.  From the men and the women.  From the cheaters and the cheated-upon.  If I let myself fall down the rabbit hole, I'm terrified for the emotional health of my children.  Did I scar them irrepairably? Will they be unable/ unwilling to commit to one person?  Do they stand a chance at happiness in their adult lives?  I've destroyed my husband; that is a complete understatement.  I made horrible choices as a wife, as a mother, as a human.  Any effort I put in now (and I do) seems like a day late and a dollar short.  Lessons that are learned in childhood are incorporated into one's whole self - our self worth, our self esteem, our sense of who we are and how to get along in the world. 
It just tears me up that during these criticl junior high years, our son might be learning all the wrong lessons about himself and the world without the coping mechanisms in place to challenge those things.