It seems like you certainly have your hands full (I know, understatement.)
I found a really great book that may be helpful to you about bipolar called, "Loving Someone With Bipolar Disorder," by Julie Fast. My mom has it and I found this book to be very helpful for my father and I to really understand what she is going through and how to work with her.
There are many medications nowadays for it. I also have a close friend with it and both of them are on a combination of medicines, but not the same ones. It's really a matter of working closely with the doctor to find what works best for your son.
It's not just about medications though, it also has a lot to do with environment. Getting clear about what his triggers are and what things help keep him centered. The book talks about the use of exercise, yoga, meditation, etc... to keep a sense of balance. Sometimes there are foods that can trigger or exacerbate both bipolar and ADHD (my daughter has ADHD.) Refined sugars send my daughter out into orbit, so we keep those to a minimum, but omega 3 helps tremendously. We haven't gotten that far with my mom for too many reasons I won't go into...
I would be very careful regarding the influence your husband has on your son given he's still "dabbling." I would be reluctant in your situation to have him in the house. Your son needs stability and consistency in huge doses along with the meds, please consider your options with this for your son's sake. I hope I'm not overstepping bounds, I'm just concerned.
My last thought is something you are probably already doing. Counseling to help you, your son and your family cope with these issues. That would be the best way to know how to tell people and more importantly help you and your son find the best ways to work with his challenges. You need to also come up with ways to keep your health and well-being intact through all of this. You're dealing with some pretty big life issues, I imagine you'll need support. Don't be afraid to ask for it...
My Heart goes out to you and your family.