Please check paragraphs

Teacher, I am writing notes about my working experience last year. Can you check for errors. Thank you.

Last year has been a tough year for me. Working as a temporary assistant has been challenging as I covered different assistants when they were away on holidays. On many occasions, it was stressful as I had to complete the required tasks within a certain time. When I received telephone calls I had to figure out who the clients were and to know their files quickly. The more desks I cover, I know I will gain more working experience. I have learned how not to panic and to tell myself to deal with the urgent tasks first and then the remaining tasks. Overall, I think this job stimulates me and keeps me motivated to learn new things.