My Christmas job or was

My Christmas job was to work as a Christmas casual postal employee for 3 to 4 weeks. I only lasted through last week due to the job being too physically stressing for me. I can lift 70 pounds but it stains my body because I am thin don't have a lot muscle and I was thinking that I may also be underweight or too thin for the job as more body weight would make it easier to lift and move 70 pounds or more of mail bags,  and those cages called GMPCs and OTRs.
I kept being moved around to different sections to so a supervisor can see if I can do the job and my performance was suffering a bit as I felt like I wasn't performing to their standards, as in some of my past jobs, I was always a bully target for being accused of lack of job performance or being called slow if I did not learn fast enough. I thought I could go to work every night for 3 to 4 weeks, perform the best I can, then come home. Not the case.
There was also another supervisor that started harassing me about my performance and accused me of standing around in the scanning section where I was working. The next night after that I was working in the mail hashing section and the night after that, he came over and harassed me again about not keeping the floor clear to traffic. I was lining up the hampers of outgoing mail going over to the scanning section  and they were full.
I was already getting frustrated with his harassment and singling me out. Later the other supervisor from scanning moved me to 2 other sections. I was almost to tears, stressing and frustrated. I felt like I was unfairly being picked on maybe due to my thin weight, I don't know. Maybe they thought I looked like a slacker or my appearance has the slacker look to it. I resigned that night which was  Friday night.
I have an interview for another postal job i applied for, so I'm going to have to see that I can reschedule the testint for the communications dispatcher postition for the Washington State Patrol. The interview is earlier that morning and I will not have to time to make it to the Washington State Patrol Academy in Shelton for testing.