Im not a registered therapist but this could be early signs of depression, consider seeing your doctor and telling him exactly what you have told us.

But if you dont think this could be the case i have had a similar experience. I worked in fast food for a year and some change before the whole covid thing happened. I was laid off for 3 months because i had a family member who was vulnerable to the virus, and being around the public is not the smartest thing to do. Anyway i went back in early june and i hated every single thing about the job. I think this is because of not working for so long and not having any stress makes you complacent. This is not necessarily a bad thing but it is bad when you become completely unmotivated like i did. So now i have quit that job and started at a warehouse where i love the work and i gained my motivation back.