Hi, I'd like to help you with your question.
Your son's behavior is causing you a lot of stress. You are trying to balance being a loving and supportive parent with the stress and grief your son is causing. That is a very hard place to be in.
It is important that you care for yourself. You mentioned doing some things like staying involved with grandchildren, resting and staying busy. All of those are great responses to the stress. But you also need someone outside of your family to talk to. A therapist can provide you with an objective point of view, suggestions on how to handle the situation, and overall support to help you through. To find a therapist, talk to your doctor to ask for a referral. Or, if you attend church, your pastor can help. Pastors are often trained in counseling and can offer you support with your faith as well. Or you can search on line for a therapist at http://therapists.psychologytoday.com/rms/.
By seeing a therapist, you can also address some of the long time issues you mentioned. This will help you find different and better ways to cope with your family situation.
You also should decide your boundaries with your son. Being supportive is great, but if your son is making poor choices than he needs to not put you in the middle of the situation. That makes you responsible and causes much guilt and stress for you. That is not to say that you should not be there for him, but deciding how much support you can provide helps you and him with boundaries. For example, support your son by being there for court and for helping him local a place to stay when he is out. But draw the line at having him in your home. By having him there, it takes away the very place that is your safe haven. You cannot go home and relax from the stress of the situation. You are living with it 24 hours a day. That is a lot.
Also, by not providing a home for your son, you are helping him. That sounds strange, but you help him by forcing him to be more responsible for his behavior. If he feels that you will always help him when he does the wrong thing, then he has less incentive to do the right thing. But if the consequences of his actions all fall on him, then he has to take the full brunt of his actions.
You are in a difficult position and it is understandable that you feel this way. But there are options. Reaching out and asking for help shows that you are approaching this in a healthy manner and that you are open to changing the situation. And those are signs of a healthy way of handling your problem.
Let me know if I can help any further,