I recommend applying for a promotion early, even if you don't think you're actually ready. It's valuable just to go through the experience end-to-end.

My other suggestion would be to learn from my mistake and be realistic about your relationship with the company. It's filled with a lot of great people and they build a sense of community, but at the end of the day it's a business relationship, so you should decide what you want out of it and work towards getting that.