I am sorry you have a plateful off health issues on top of depression. I'm in the same boat. I will tell you it is a hard journey, but it will ease up over time. My health isn't even half as bad as one year ago and I'm not sure how it happened, but it does get better! Treat yourself and your body gently- In no way is your body telling you to give up. It could be telling you what it needs and what changes are required, but definitely not to give up.

I understand your perception of others who are worse off, facing starvation, fatal diseases, lack of clean water, etc. BUT....you have to remember you are one person. You are the main character of your story and you do not deserve to suffer. Your story is unique to all others and everyone has a right to a journey and their own struggles.
My Therapist put it this way: Working on ourselves when we are in in the darkness, taking care of ourselves, facing all of our monsters, learning to cope and survive, learning to remain mindful...all of this is so necessary. If you care for yourself and work on getting back to your quality standard of living, maybe you could help those struggling for food, water, clothing, etc. We must fight our own demons and work through these problems in order to find the strength to make a difference in the world.