What you have described is extremely similar to how I have felt for at least two years.
For me, I don't truly believe that death promises anything other than an end to us. From that perspective, I figure as long as I can bear the feelings that fill this time in my life, it's just kind of silly for me to act on any of those thoughts, as there is overwhelming evidence to support that one day I can actually be free of much of what distresses me, saddens me, and tires me out these days. If I were to act on those thoughts, this is all my life would ever have been, and I would be complicit in cheating myself out of happiness.
The other big thing that stops me is an honest comprehension of what it would be like for those around me in the wake of my doing that to myself. One of my group of friends essentially killed himself. To make a long story short, he had a time when hope that had been denied him came into his life due to medical advances, but sadly it did not work for him. He lost all hope and went into doing nothing but drugs and playing video games, I believe, fairly positive actually, to just get what he could out of what was left til his health gave out. We all still feel that to this day, as you might expect. For one of us to do it suddenly and quite obviously purposely would just be adding pain to the rest of our lives. No way around that.
So for now, I am really living for them, until I hopefully find my way out of this pit and into the sunlight for what will surely feel like the first time.