Get rid of the stuff that's holding you back.
What have you outgrown (not in a physical sense, unless that's somehow relevant)? Think on it. You are still allowed to MISS what you've outgrown, but that doesn't change the fact that you've outgrown it.
On that note, what DON'T you miss? Use that as a force to push you in a better, more positive direction. We all have memories of days, months, and even years we'd rather forget. Perhaps you'd like to wash away some recollection of pain or misery? The thing is, in NOT forgetting about it, we become stronger people. So, don't erase. Instead, remember. And then ask yourself, "Why don't I miss that?" And use it like a tool to propel yourself forward.
What aren't you quite ready for? Be honest with yourself. It's okay to realize you're not exactly ready for everything all at once. Not many of us are. It can still be a tangible goal, whatever it is you're not quite ready for--because you just have to tell yourself: I'm not ready for it YET.
And finally, when all these questions have been asked and perhaps re-asked, ask the most important question of all: What are you looking forward to?
What are you waiting for? I can't answer that FOR you! :)