Please re read sadtoo's post.... then go back and read all the posts from you and responses from people here, who care about you.
Yes, we are a community of people who by and large, never meet, but that gives us the ability to looks at your posts with a clarity that isn't possible when you're stuck right in the middle of it.
This time that he's locked up is the perfect time for you to get yourself sorted without having him to confuse you and cloud your judgement.
Please, step away from him, needing him, worrying about him, wanting to hear from him, worrying about whether he's taking his meds, where he'll go on release, wondering who he's phoning when he's not phoning you.... worry, worry, fret, fret, hurt, hurt.... this is no way to live.
Please don't take offense, but you are incredibly dependent on him, and he's just not up to the job, he's far, far, too damaged.
Fixing him is not your job.
He might have been great to start with but look at how he is now, maybe the "great guy" was a facade, and what you see now is the real deal....
Is this a person who is a loving partner for you and a loving father and role model for your son?
He has chosen to walk the path he's on, he always had the ability to go a different way, but this life is of his own doing. I realize his parents were abysmal role models, but he could have looked at them, and their life and wanted different for himself. Please try not to let history repeat itself again.
Fixing him is not your job.
If this was happening to your friend, what would you tell her to do?
Take the advice from tushnurse, get yourself all the help that's available, contact the social services that can make this transition a reality, lean on your family, who care about you. You don't have to just imagine a life without the stress, drama and heartache that you have right now, that life can be yours.
Hugs honey, do this for yourself and your son.