write an email about work experience

Hi Dave,
I am writing you because today I begin working  again after 3 years without a job. As you know I was very worried because I didn't have a job for a long time, but now I have a new job.
Finally I am a firefighter; this was my dream job since I was a child. Now I can help many people as I wanted.
On  my first day I worked for  24 hours with my partners, I am really tired because this is a very stressful job but also I am satisfied with my job.
I only want to tell you that this experience, although it has been hard, it was worthwhile, and I encourage you to follow your dreams.
Bye for now Dave.