I have a tendency to worry about things not worth worrying about. Recently, I've been finding myself worrying about things I have to do in a few months, which cannot be done now (such as finding a storage facility to store my stuff over summer break).
I'm trying a new strategy and hoping it helps. They say writing down stuff you're worried about and then not letting yourself worry outside of the time your writing is a good strategy. I'm writing things down in my planner for when I should start worrying about them: when I can actually do something about it.
And then I'll stop letting it cross my mind.