I have an Excel worksheet that is protected with a password, and unfortunately, I can not remember it. The file contains some important data that I need to access urgently. I have already tried a few online tricks, but none of them seems to be working properly. Can anyone suggest a reliable way or tool to unlock a password-protected Excel sheet without losing data? 

If you can't open your Excel sheet, I recommend trying the Softaken Excel Password Remover Tool. This tool instantly unlocks your sheet without any data loss.
Simple interface
Supports all Excel versions (XLS/XLSX)
Fast and secure process

I've used it myself and found it to be very reliable. This is the best solution for files you own.

Blog:- https://www.softaken.com/guide/freeware-excel-password-remover-launched-with-powerful-features/