Technically, summer doesn't start until next week, so if you haven't done any of the things you want to do this summer, you aren't behind!

Try to focus on a few things:  books you'd like to read, craft projects you'd like to finish, parties you'd like to throw, trips you'd like to take, cleaning projects you'd like to complete, etc.  If you try to do everything, you'll typically achieve nothing. 

So give yourself a break, choose a few things, and enjoy!