MS Outlook appt forwarded from work to home. Can't delete

My boss added a meeting to Outlook then sent invites to people. (at work)

I accepted the meeting then forwarded to my home email (not outlook)

(It gets forwarded on his behalf).

So now he has left. The meeting shows on my phone calendar but has a line thru it (I have opened and declined it) and it is faded gray.

I cannot delete this from my calendar.

How do i get this meeting to go away?