幫忙寫一封英文辭職信

先說說我辭職原因，由於在這家公司工作了一年多！做得有點不開心！工作苦悶，跟同事相處的不太愉快，加上一年多了薪水還是沒漲，一個月只有兩天假，星期六日也沒假放，每天早上八點上班加班到晚上八九點，機器也需要充電吧？我真的累了，連美好的星期日也得上班，我已經忍了一年，夠了！
以上不需要翻譯～我想寫封客氣點不要抱怨太多的辭職信，走之前也需要給人個好印象！
想求封簡單明了的英文辭職信

Dear Mr. X,It is really a hard decision for me to tender this designation to quit my position as the administrative manager in the company with effective date from (the last date) due to XXX(或because XXX).Thank you for giving me a chance to learn and to gain the valuable experience in (company name and section work with). I hope my resignation would not cause you much inconvenience. Thank you for your kind attention and would appreciate if you could let me have a reference letter before I leave. Yours faithfully, ________________(your full name)

以上這封我覺得還不錯，簡單又明了，可是內容對我來說好像有點不太對，我只是小職員，不是什麼經理，應該怎麼寫呢？糾正一下 最好翻譯