Accepted a job with no motivation to start?

I accepted a seasonal position at a Halloween store, I know it’s only two months of work. For backstory, I’ve been out of work since January, I hit a burnout in my full time position and wasn’t treated properly, so I quit. I’m dreading to start this job and it’s causing me to panic. My dream has been to start my own small business and have slowly gotten it off the ground during winter time. I need to do this job but I don’t want to be miserable and let my misery and anxiety get in the way of me being able to work. Any advice would be appreciated. Thanks