I went thru some of this years back. The only way I could really detach was to realize that my son had some really important life lessons to learn and they were not from me. Some wonderful people here on SR helped me to understand that I could love my son right into his grave.... and that I needed to step back and allow him the joy and dignity of his consequences for his own behaviors and choices.
I've said it before and I'll say it again. This mom stuff ain't for weenies.