I am in a similar position. I come home from work and am mentally exhausted. My boss clearly does not like me but keeps me on for reasons that I don't understand. Most temps are hired after 3 months but she is requiring me to do 6 months. I have 2 more months to go. Everyone else is nice. At my age - I'm almost 60 - this is a huge physical test as I have no paid sick or vacation days, nor do I earn any as a temp. I don't know whether to start looking for another job or to stay the additional 2 months to see if she keeps her work. I doubt that she will.

My only suggestion is this: stick it out and make sure you get as much rest as possible after work. See if you can stick it out and keep looking at new job openings posted in your current company. After a year, consider applying for a suitable new position. If you cannot stick out a year then start looking elsewhere. Another suggestion, see if you can delegate some of the responsibilities of your new job after you have mastered them. This will help limit your responsibilities though you will still have to supervise. I wish you the best.