Welcome from mom of 23 yr old AS.
I've met many parents through my al-anon parent's group. Death, jail, insanity or recovery are the options for out adult addicted children. One of my best friends that I met through this group 5 yrs. ago has a son who has been in and out of jail + prison numerous times. She accepts this and knows when he is "in" that he is safe, fed and off meth. When he is in and they talk on the phone, she is having a relationship with her son and not the addict. Her son is 37 and has been sober for a yr. It takes what it takes.
Most addicts rack up legal problems and many only change after jail.
Don't focus on "how am I going to deal with the possibility of a long jail term" because this may well be the intervention that is necessary.
If there is a Parent's focus Al-anon group near you, it could be beneficial. It has been a blessing for me and I've made some wonderful friends there. Being able to talk about stuff and work the 12 steps through this program has changed me in many ways. When I focused on myself, change became possible for the only one I could change, myself.
My son just completed 6 weeks of a yr. program. There is hope. We all come to recovery on our own timeline.
Please stick around to share with us.