Hi Beth,
It sounds like you've entered a nihilistic thought cycle. It's very tough to break! The fact is, at some point, you will need to fake it until you make it. You'll have to break out of your pattern by adding new activities and routines, and you'll hate them at first! The cliche is exercise, but it really works once you see some change! Another secret weapon I like to prescribe is Synthesia - ask me if you'd like to hear more.