Thank you. I realized that this might be the only or easiest solution, but I’m concerned that I will lose my emails and contacts if I do that. What do you think?
You will be fine. IMAP accounts are just synced copies of what is on the server.
If you still have some concerns, then make a backup before you remove the account. You can do that through Menu > File > Backup. If after removing and re-adding the account and allowing the account to re-sync, you are missing anything, you can restore using Menu > File > Restore.