If you've started this job recently, that sounds completely normal, at least to my neurodivergent ears.

You're learning how to ride a bike, except it doesn't require so much physical practice as mental practice. You're putting in a lot of mental effort all day every day, and it's exhausting. For me, this period at a new job can last three to six months, sometimes more. Eventually, you get the hang of it, and you don't have to put in nearly as much mental effort to do your job well. Then you can get back to your other life shit.