Hi SC- I'm no expert but I agree that your H is limiting contact with you this month because he isn't sure how it all is going to effect him plus he doesn't want to feel bad if you do get "emotional". However, knowing there will be limited to no contact with him, you will have no expectation and fewer disappointments. Hopefully that will make things a little easier on you.
You do have a lot on your plate right now but you seem to be handling it with a lot of strength and grace. You already know that there will be brighter days ahead regardless of what happens with your M. It took me almost a year after the bomb to really accept that. Each day I have gotten a little stronger although there are days (like yesterday) where I still have a major backslide.
Is your S17 acting out because of the family situation? My S17 went through a stage where he was drinking and smoking pot last year...that was tough. I hope that your S17 will continue accept the help he is being given and separate himself from the "friends" that are really anything but friends. Is he graduating this year? If so, what are his plans after he graduates?
Are you doing anything special for your birthday? It is a great excuse for you to pamper yourself in some way...or maybe find some friends to go do something new and fun.
Keep moving forward and continue to focus on that light at the end of the tunnel...it will get bigger and brighter.