Using Classic Outlook on Windows for personal email, calendar, and contact management
Sorry to hear this. An Office repair normally does not delete calendar items; Outlook may be displaying a different calendar/profile or may no longer have the original data file attached.
First, please check whether the appointments appear in the account’s web calendar—for example, Outlook.com Calendar for a personal Microsoft account. Then, in Classic Outlook, open Calendar, expand My Calendars, and confirm that the calendar belonging to the correct account is checked.
Also check File > Account Settings > Account Settings > Data Files and share a screenshot of what appears there, hiding your email address. Please do not delete a profile or data file yet. If this was a POP account or a calendar labeled “This computer only,” the appointments may be stored in the original .pst/local data file rather than online.
I’ll be waiting for the requested information so I can continue helping you.