Has anyone here worked in the social services, and experienced the death of a client?

I am a case manager working with people who were formerly chronically homeless and are now in housing. I have been there just 10 months and have had two clients pass away in that time. The first one was an amazing experience for me. It was scary and upsetting in the beginning when they started to get sick, but because I was able to help them reconnect with family, and to do a lot of things to help them transition over (bring in spiritual leaders, surround them with things that were sacred to them, etc...) it ended up being a very healing and special experience for me. I found peace in it.

This time around, there were uglier circumstances surrounding the death, and it's been traumatic for me. I don't mean to make my client's death all about me, but it impacts me. This person was being mistreated and used by another person (they knew it, but weren't really in a position to make decisions for themself). They stayed trapped in that situation because of an addiction that impaired their judgment. And they refused medical treatment. I knew they were very sick, and tried to get them to go to the hospital several times in the days before they died. But they wouldn't go. I talked to other staff members to try to get ideas on how to motivate them... nobody said anything but "they can take care of theirself" and "they're an adult, there is nothing you can do." They weren't able to take care of themself in the state they were in. IMO, they weren't capable of making decisions about what was best for them. But this person was an adult, and there really was nothing more I could do.

Still, I am left with guilt, and tremendous regret, and a feeling of powerlessness. Not to mention, I am sickened by the person who was mistreating them, and the ugly things that happened there. And I keep asking myself if there was something, somewhere along the way in my work with them, that I could have done to impact this situation. This life.

My job is so hard.

And here I am, applying to graduate school to become a psychologist. What will I do if I have a client someday who dies of suicide? How will I cope? I'm not sure I am cut out for this field.