I like the above grammatical changes Stephen has suggested. You may also consider rephrasing your last sentence from the current wording to something like the option below. Then close the letter by summarizing your personal need of protection and thanking them for reading your letter of application.
"The only way which is left is mostly to protect myself, but it's hard when I am not allowed."
to:In summary, my basic need of, "self protection," is the primary reason for application of the CCW license.
Thank you so much for accepting my letter of application, and I look forward to discussing any considerations or concerns you may have regarding my application submission.
This is just my opinion but, gives the reader the seriousness of your reason for application, and thanking them for at least reading your letter of application.
Then close the letter with, "Sincerely or Respectfully" and your name, with your contact information directly below your name so they can reach you if necessary.
I hope this helps.