be chasing your tail
be chasing (one's) (own) tail
To be taking action that is ineffectual and does not lead to progress. Refers to how a dog can exhaust itself by chasing its own tail. Come on, Bill, go to sleep. You're just chasing your tail at this point, but you might have a breakthrough with the research if you take a break from it. I've been chasing my tail on this project because so many components of it are just not working out.
be chasing your tailor
be chasing your own tail
If someone is chasing their tail or is chasing their own tail, they are using a lot of time and energy but not achieving much. I'm more relaxed now. Before, I was chasing my tail like some sort of lunatic. I've been chasing my own tail all these years.