I submitted my letter of resignation and was advised not to resign. However, if I were to retract my letter of resignation, just because I was advised to do so, I would not have submitted the letter in the first place.
ご質問ありがとうございます。
"I submitted my letter of resignation"＝「私は退職願を提出しました」
"and was advised not to resign."＝「そして慰留するように言われました。」
"However, if I were to retract my letter of resignation,"＝「しかし、もし私は退職願を撤回するとしたら」
"just because I was advised to do so, "＝「慰留されたという理由だけで」
"I would not have submitted the letter in the first place."＝「最初から退職願を提出していなかったでしょう。」
アメリカ合衆国 
