The stories that I want to write about are big, and would require tens of thousands of words in order to properly portray. However the most words I managed to write for a particular story was about 4k. I would like to be good at writing someday, but from my past experience, working on any kind of big project has resulted in abandonment of said project.
I figured that all I had to do was to work on something smaller, a short story. However, I find it near impossible to think on a small scale. I can brainstorm a bunch of big ideas, but not small ones. For example, one of my stories was about two orphaned siblings trying to survive in the world. Every chapter would feature a perspective shift, and one of the two main characters would meet someone that taught them something about life, intentionally or not. The "big picture" point of the story was there are some problems in life that cannot be fixed, but there are ways to deal with them.
I like this idea, however it's just too big for me to really write, and I don't really see a way to shrink it without having it lose meaning.
What should I do, really? Should I just find a way to write the stories that I want to write, or should I force myself to write smaller ones?