While the system here in australia is different the same basic things can & do happen. I've been in situations like this although not nearly as bad.
First i'd talk to your gp (local dr) & see if you can get any help/suggestions of starting points.
Next do you have what we call "community centres" or "health centres" these sorts of places are run by local, state & federal government here & often have lots of information or access to it that we just don't know.
Last, doesn't the dr/hospital have what we call "a duty of care"? Here that would mean that if they release someone without informing those who will be providing care (the patient doesn't count unless he is mentally aware/not medicated to reduce mental alertness) of all od the needs e.G diabetes & what's required plus the internal bleeding. Further here I believe that a dr/hospital could be sued for failing to advise you of this & also for releasing him without ensuring that internal bleeding had ceased.
So talk to a lawyer about that (do you have free legal advice centres where you could get some initial information on this without the risk of huge costs?).