You sound quite similar to me! Except what happened to me was I went from being somewhat positive to COMPLETELY negative (I put it down to the junk food which is all I ate for almost two years, and divulging in conspiracy theories), then back up to SO TOTALLY AMAZINGLY POSITIVE for the past good while. I always say "I can" now and haven't thought anything is impossible for the last 2 years.
I wanted to fly: I started LD'ing and OBE'ing
I wanted to be smarter: I study hours a day and learn more each day
I wanted to be successful: I'm an A student in college now thanks to being positive about absolutely everything I do
I wanted to be stronger: I worked out and have doubled my strength so far
etc.

Anything is possible, and everything is an opportunity!