How to make a salary inrease letter?

Hi, can anyone help me check my letter about salary increase if this is ok or maybe a said something wrong. Please help me. Thank u so much.

Dear sir/madam,

First of all, i would like to apologize in advance if I get an incorrect grammar or words according to this letter as this is my first time to right about my following request. I am here to ask for a request about increasing my salary. I am very confident that ive been working in the company for being independent, trustworthy and a hard working person for the past 10 years as a musician. The reason is that, since i am now a parent and a single mother, it has been a struggle and having a hard time with all my expenses, especially for my child. Im sincerely hoping if you could help and give me a chance to increase my salary from $14,500 to $18,000 if that would not be a trouble. I can't thank you enough for making me a part of this company and I want to apologize again for making this request all of a sudden. I hope u understand. Thank you so much for taking your time to read this letter.

Sincerly,
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(Singer of 6th Dimension)