A little background here..I worked at my last job in a warehouse for 8.5 years. Never got promoted (nor did I try because Level 1 associates made more than supervisors bc we were always on mandatory OT.) My drive was a hour each way and if traffic was bad (usually was) and/or an accident (major highway with tons of tractor trailer incidents) then it’d turn into an even more of a awful commute.
This past year I got two surgeries on my ear to restore my hearing and each time I came back from leave, I was miserable. I also dealt with back and hip issues which were directly from the labor at this job (which I managed to get under control while on leave by losing weight and exercising)
With the constant changing mgmt and unattainable goals (+ I had supervisor responsibility as a level 1 associate.) I found another job 25 minutes from my house to work for the state at a direct care facility.
I had so much confidence till today (my 1st day of 3 weeks of classroom training.)
Everybody in the class has prior experience and are able to understand the paperwork and methods but I can lost. Did I make a giant mistake? I’m freaking out and was sweating non stop during the training. I feel like I made a giant mistake. Plus bc of seniority I can’t get the days off I might need. I feel like I jumped the gun because of how miserable I was previously.
The benefits are great and as time goes on I make up for the pay cut I took plus health insurance doesn’t cost a thing and I get a pension. 
Am I just overthinking this?