So far, all the advice here is that you can be good if you do the right things. Since your post asks something a bit different, I'm going to tell you something else - get out.
Seriously, get outside. If you're in college, go join an intramural sport. High school? Find some people to hang out with, or immerse yourself in interesting electives.
Competitive smash isn't for everyone, and not everyone in competitive smash plays for the same reasons. Some people in my scene will settle for no less than first. I'm content playing a character I love and doing crazy stuff. My best friends enjoy nothing more than item FFA on Hyrule Temple.
So, if you don't have the motivation to keep playing... Go do something else. Get a new perspective, and maybe you'll come back with a clearer image of what you want out of the game.