Happened to me to, OP, tho within a shorter time frame. Interviewed by two people. Hired. By the morning of the first day it was clear that of those two interviewers one did not want me there. Unfortunately, she was designated my direct manager. She gave me no induction, misled me on simple questions and failed to brief me on basic matters such as permission to drive the office car. I struggled on for four months, then quit.
Had she been my employee in my previous job, I would have managed her out. But in this case, the roles were reversed, so off I went.
Sometimes you hit a bad work situation and all you can do is coolly and gracefully resign. Sounds like you've done that. Alas, these happenings are now a la mode in the shitful modern workforce. Please do not internalise this, hard tho it is to handle. It can be a personality thing, an employer-being-disingenuous thing or a numbers on the payroll thing.
If you're reverting to a less-pressured role, have a look sideways at some new skills you might acquire. Look at emerging industries such as security.
I started full-time work in 1985, and the workplace is so, so different now. Employers (in my experience) used to be brilliant in training and promoting their people. Now they just whinge and gripe and demand to bring in low-paid migrants instead of looking at who of their current workers has useful experience and could be quickly trained to do a new role.