Waaaaay easier said than done....that said, what is your focus and the reasons behind that choice? Go back over your reasons; if the decision is still sound, at least you know it's not that your interest is moving away from your focus.
Is your "creep" toward a logical expansion/broadening of your current focus? Other than that, the most common deviation I allow is a strategic acquisition that I know I can sell or trade for more value, poured back into my collecting goals.
And of course it's okay to still be a reader. If I see cheap books I've always wanted to read, even if I know I might lose a few dollars turning them loose again, that has to be okay sometimes. Mind you, I'm not buying gold and silver keys to read once and sell fast at a loss, but I'm talking about finally finding that short run that ought to be in a dollar box, and it's six books at $3 each instead, or somesuch. At that level, it's just entertainment consumption like anything else from a book to a movie to a class to a bucket at a driving range etc. Whatever your other hobbies may be.
Hope this helps you kick it around, especially since your boardie name was my favorite Thunder Agent!