Susan, Hugs to you. You've really had a hard time with this. My best advice is NOT to even contact your son. You don't have to run to him every second of every day of his life. Your son knows where you are and how to contact you. HE IS 24 YEARS OLD! A grown man!
In your heart of hearts can you honestly answer the question........... Do I really want my son to grown up and to be morally and mentally sound? If you answer yes, to this question, you'll know that you have to let HIM do that on his own without you interfering in his life and enabling his bad choices.
If you answer no, you'll continue to do what you have always done, cry, fret, rescue, take care of mama's little 24 YEAR OLD BOY!!!)
I wonder why it is that your WHOLE sense of self is wrapped up in mothering/babying a 24 year old grown man?????????? That is a huge problem! This is your problem Susan and one you need to look very closely at more than likely with a skilled therapist.
You are so much more than a 24 yr. old man's mama! Aren't you a mother to other children too? Don't they matter as much? Aren't you also a teacher? Aren't you also a WIFE? I'm pretty sure I've read that you have a counselor.
I feel pretty certain that you need to change and find someone else and you need to see them often. I really feel that you are in crisis mode and have been for some time. Susan, you need to do this for YOU! Please let us know that you have sought out help for yourself. {{{hugs!}}}