You've done the right thing. Hard choice to make, but it will keep him alive.
And that's the point of suicide-based admissions. It depends on the hospital - here, the public system will discharge you as soon as they consider you safe enough, and that's likely to be sooner if you have a spouse to go home to. Private hospitals will tend to extend the stay, especially if he needs to come off meds before starting new ones.
It's hard to predict, because it's a juggling act with a lot of balls in the air, including things like his history, his support network, and how he responds to hospital. As a general rule for ptsd, longer hospital stays can often be counter-productive. Whereas for depression, if the hospital has a behavioural activation program in place for inpatients, they may wait to see him participating and engaging again before they discharge him.
Most hospitals will engage with a spouse to some degree about treatment and discharge planning, which is good if you can get in on that. It means that you can give them insight into how he's been going (he may not be the best judge of that right now), as well as be clear with them about the situation at home that he's being discharged back to, and the supports he has in place. Check in with his nurse if you visit - introduce yourself, so they know you're around and communicative:)
For admissions like this, they will often make sure that there is a reasonable treatment plan in place (meds, therapy if applicable, daily activities, crisis management, etc) prior to discharge, and it's great if you can be part of that and have a good understanding of what happens when he walks out.
Right now, it's rock bottom. But he's in a safe place (even if it's awful, he's safe). Keep reminding yourself of that. Things got to crisis point, but he's safe now, and you're not coping with this alone.
