Relative clause confusion: "whose company I am leaving" or "who is leaving the company"


I came across this one in a study book:

本日、退社することになりました社長を初め皆様には本当にお世話になりました。

The translation reads 'Today I am leaving the company, and I would like to
thank not only the President, but everybody.' However wouldn't a literal
reading be 'I thanked everyone who is leaving the company, starting with the
president'? ie implying that the president and everyone is leaving the
company? Would this be more accurate:

本日、退社することになりました **私は** 社長を初め皆様には本当にお世話になりました。

Thank you.

