Good day Cheryl,
Since you can still see the emails on your phone, your mailbox data is still available.
Please try the following steps:
Make sure your operating system and Classic Outlook app are fully updated to the latest version.
Step 1: Check Outlook on the web
Open a browser and go to https://outlook.cloud.microsoft/mail.
Sign in with your work account.
Open one of the affected folders.
If the emails appear there, the mailbox is working correctly and the issue is limited to Classic Outlook.
Step 2: Start Outlook in Safe Mode
Close Outlook completely.
Press Windows + R.
Type Outlook.exe /safe and select OK.
Open the affected folder.
If the emails are visible in Safe Mode, an add-in is causing the issue.
To disable add ins:
Select File > Options > Add-ins.
Next to Manage, select COM Add-ins > Go.
Clear the add-in check boxes and select OK.
Restart Outlook normally.
Step 3: Create a new Outlook profile
Close Outlook.
Hold Shift while opening Outlook.
In the profile window, select Options > New.

Enter a profile name and add your account.
Open Outlook with the new profile and allow it to synchronize.
Step 4: Repair Microsoft 365 apps
Right click Start and select Installed apps.
Find Microsoft 365 Apps > Select Modify.

Run Quick Repair first.
If the issue continues, run Online Repair.
Restart your computer.
If you have any questions or need further support, please don’t hesitate to reach out at any time.
Thank you for your patience and understanding.
If you have any extra questions about this answer, please click "Comment".