Please comment on my letter

Topic: You work in a busy office. Recently one of your colleagues has resignesd, and your workload has become increasingly heavy. You are working overtime every night, without receiving any extra pay or recognition
I am writing on behalf of a staff in the company, to enquire whether you could possibly handle my workload-related problems as my co-worker has just left his position.. Write a letter/ email to your line manager explaining the situation and asking for action to be taken.

Dear Sir/Madam,

Specifically, due to my teammate's immediately resignation, not only do I have to manage my project but also take over his inconclusive piece of work. So dense is the affair that I have coped with it by taking on several night shifts. This can be manageable at first, but in the long run, I find that excessive workload makes me struggle with physical and mental health problems. I am always put under a lot of pressure owing to the fear of not finishing the projects, leading to insomnia and powerless. As a result, it is difficult for me to stay alert on working each morning. Therefore, it would be grateful if you could hire more staff so that the workload could be shared equally.

Furthermore, although I always make great effort to ensure the outstanding work and bring the best merits for our office, my attempt seems to be totally neglected since no appreciation or rewards are given to me. Gradually, I no longer have self-motivation to keep pace with my excessive workload. Thus, what I really would like to know is whether you can offer financial incentives or merchandise rewards to employees. It is undeniable that a key determinant of a company's success lies in its level of productivity, so developing good employee attitude amd creating incentives for them will be of great help to improve business's productivity and effectiveness.

I feel sure you will agree that, only by guaranteeing the equal distribution of jobs and rewarding staff for their dedication can employees strive toward making company successful and profitable, as it goes without saying that satisfied workers tend to be more productive.

Thank you in anticipation of your kind cooperaton. I look forward to hearing from you at your earliest convenience.