I have gone through times like you describe, where always, my last thought at night was 'I wish I could die'. That went on for years actually. And like you, not because terrible things were going on in my life, I was just tired of (in my case) being in a world where there is so much pain and hurt going on all around.
I think what helped me start to feel better is I began to wonder if I had just worked myself into a habit of feeling blue all the time. Gradually over time, I've learned to say to myself, when those intruding thoughts and sadness try to creep in, "I don't want to think about that".
I think there's something about saying those words to myself that helps to create new pathways in my brain, so right after I say that, I make a point of putting my mind on something that can make me feel good. A good memory, a song that makes me smile, a video I find inspiring, someone I love, anything as long as I don't follow that little creeping grey shadow that's trying to pull me in. Maybe something like that would help you.
As to the rest of your comment, if you want to have a chat about that sometime, that would be an interesting conversation and one that I'd certainly be up for.