I understand this pain all too well.
I, too, once wanted to make an impact to the world, you know, a grand discovery, a selfless gesture, anything of the sort - to start changing the world.
I guess I had no idea what the word ' world ' meant to me at the time.
Once I redefined ' world ' not as ' the world ', but as something more intimate - a sphere encompassing myself, my family, my friends, the people I care for - that's when I started feeling better.
I guess this happened because I could affect more people in this world of mine, and forge a path to each and every one of them, and with them, forge other ones so that we can change one another, and our surroundings.
You can also redefine your intimate world, your personal world, your job-related world, your friend-circle world, etc, but once step at a time.
This is how I started to identify a self that had a place in ' a world ', but not ' the world ' . I guess this is also the time when I stopped having favorites, as in favorite singers, movies, etc., but that's another topic.
In short, if you feel like you're failing to live up to a nickname you've given yourself a decade or so ago, there are two things, IMHO, that you can do - either change the term, or redefine what it means.
Or, redefine your world. Not everything you do needs to be significant in the eyes of onlookers. I bet that you are super significant to your loved ones, friends and family alike, you probably just need to pick and choose who to keep in your world.
Not everyone is needed in there, you know.
What I speak of may not be totally in line with your problems lined out in this post, but it has helped me get rid of emotional messes before, and a keep a lid on that depression that is always lurking.
Anyway, stay well, and do tell how you feel. Big hugs.
RE: Yielding to a Cocoon of Slumber