Sherydoc welcome. I'm so sorry about your son's decision.
Unfortunately, we are powerless to enact any changes in our adult children who for whatever reason, go off the rails.....he is a 23 year old man, your ability to enact change is limited to what your son agrees to.
It may be helpful to read the article on detachment at the bottom of my post here.
You may already be aware of these options for support......If your son has mental health issues, it may be helpful to contact NAMI, the National Alliance on Mental Illness. They can be accessed online. They have wonderful courses for parents. Many parents here find solace in the 12 step groups, Al Anon, Narc Anon and Families Anonymous. This is such a challenging path that many of us opt for private therapy, which helps us to navigate this different and difficult road. A good book is Codependent no more by Melodie Beatttie. The best advice I can offer you is to get as much support as you can. This is very hard. Most of us require a great deal of support in order to make the necessary changes we parents must make.
Continue to post. It helps immeasurably to write our stories down and then receive support, guidance, information and empathy......often out there in the real world, we're judged, blamed & criticized......but here, we get it. All of us here have kids of all ages who are challenging......
You're not alone. I'm glad you're here with us.
Hang in there Sherydoc.....take a couple of deep breaths to try to let the fear go.....if it feels right check out some guided meditations on YOUTUBE....there are hundreds, throw on a pair of earphones and listen......it can be calming in the midst of these kind of emotional storms.