Contact a family/divorce attorney after doing some research on your state laws to prep questions for your consultation. If you handled of the finances, you're ahead of the game. My husband did almost the same. He finally went to rehab, and he came home to plot how to keep all HIS money and exit. In rehab the addicts learn not to look back and guilt themselves. Some addicts take it literally, yet they are told not to add stressors.
Find out what your options are by consulting an attorney. Wish you and your son the best as you navigate through this difficult situation.