I'm so sorry about your son. I can't imagine the pain you both have suffered. I've been dealing with my daughter's sexual abuse when she was young that she later turned to drugs as a teen. This has torn my H and I apart. I started counseling 2 yrs ago and it's been a life saver for me. I would strongly suggest you seek out a C if you aren't going already. It's so important to take care of you!! This has made a huge difference in me getting my life back from depression and helplessness.
Unfortunately, my H has never delt with any of my D issues. Like you H he sought comfort with OW. In my case, my H avoids his pain or unthing unpleasant. He is running from it all. responsibility, pain and seeking pleasure and youth.
As you see here, you are NOT alone. You might try journaling your feelings too.
hurting again
http://www.divorcebusting.com/ubbthreads/showflat.php?Cat=&Board=UBB2&Number=1137408&fpart=1&PHPSESSID=