The hospital sent you home for what could be various reasons (budget cuts, bed shortages, incompetant staff or a communication breakdown etc) but it is definitely not a sign you should give up. Your life is worth fighting for so keep fighting. With the dissociation try to ground yourself in reality. Have you heard of the five sights, sounds, touch etc? I find it helpful when I dissociate. Focus on locating five things around you for each sense and try to experience each one. This helps ground you in the present reality.

The stress you are under must be overwhelming so you are going to have to pull out all the self-care, CBT, DBT, mindfulness etc skills you know and put them to practice. Fight against the strong urge to give up and stop trying. You can do this. The key is to do no harm to yourself and stay alive until help arrives or the episode passes.

If you get to that point where you are planning to end your life please call 911 and be abundantly clear of your intentions. Stating plan and intent should get you a bed somewhere. I would be horrified if it didn't. Keep trying to get help, keep fighting. This will pass.