The nearest to a positive sentence I can come up with is "I don't know what to do with myself, he doesn't know what to do with himself" etc... but of coures, since they are examples of reported speech, they're not positive/affirmative sentences! I don't think you'll ever find that expression in an affirmative sentence, since it's used to ask what you are doing, so the (positive) answer will use the verb that describes your occupation.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.