I've had depression for nine years. It will be the ninth anniversary of dropping out of University in three weeks time. It doesn't feel like nine years of course. Nothing having a job and being at home means it feels more like centuries. If you were watching it on TV- it feels like the first part of my life is a five minute window followed by hours of static. They don't have equal weight although there are some positive experience that feel very vivid. I used counselling twice when I lost confidence in myself; the first time was when I left university, the second was when the guy I developed a bi/gay crush on became an arms dealer. You don't need a lot of imagination to realise the second one was the closest to being suicidal because it screwed with just about everything I believed about myself, the world and the guy I was in love with all whilst trying to come out as bisexual. It passed though and I have never used medication because I "wanted" to experience the symptoms. If you know what the symptoms are- you can figure out what's causing them and have much greater control over the recovery process.
I can relate to what you say about suicide. It does take a refusal to give up, which is often deeply irrational but you have to accept that you are worth fighting for. I remember that when I was suicidal, I would joke to myself "if life really is that futile, what's the point in killing yourself? leave it till tomorrow". Its black but it kept me going as the desire passes. its all about wanting to escape so there is a kind of balance between not doing it and accepting its there. The biggest part of the problem is the unreality of suicide because thinking about it is if you are someone else watching yourself doing it. There is that disconnect. When you start to get past it, it becomes more "real" and much more difficult to think about.
Anyway, I'm not trying to burden you with my problems. I'm just sharing so you know you're not alone.
If I can give you some advice, I think that if you are working with and therefore surrounded by people who are suicidal, it is entirely rational to take its toll because people are trying to live off you. Its not your fault. You can do something for them but you owe them nothing. I found it is important that to survive you have to be a selfish ****. It doesn't mean I don't care or that I don't get hurt but it can put some distance between myself and others and have good boundaries. There is a very painful sense of having to let go and accepting you can't control the situation. You've probably already been through this a few times if you heard a patient died.
There was a clip from an episode of House MD ("Three Stories", Series 1, Episode 21) where Doctor House is lecturing a group of medical students and he said that you have to be prepared to lose some of your patients. It stuck with me because it put the idealism of wanting to "help people" in context. I think as your in a situation with suicidal patients, it may be worth taking a step back and ask whether you should refuse to lie down and "die" by watching others do it to themselves. If you're in an abusive relationship you have to know when to end it. The difference about the doctor-patient relationship is that you're not in a relationship with one abusive person but many. Just because "everybody lies" doesn't mean you have to go along with it and buy into the myths people make up for themselves. The danger in wanting to help people is that you become co-dependent and feed their myths in exchanging for feeding a belief in your own myths. It takes a lot of ego to want to help people and that isn't necessarily a good thing. Its about deciding which is more valuable, the illusionary self based on good intentions, or the life you could have by trying to have good consequences that make you and others happy. Its not easy- but its your life.
I'm assuming you included the fact you're suicidal in the OP as that was a cry for help and that something happened recently that's brought it back to the surface. I'm hoping my advice- even if its almost certainly unwelcome- may give another perspective.