Opening a password protected excel file.

Hi Everyone.

A little while ago, I protected my sheet to prevent someone to modify it and I'm 100% sure the password is correct since I made sure to keep my password on my phone. When I wnat to modify it this afternoon, the password didn't work (I've tried to write the password on Notepad to make sure that I have the correct password). I googled a way to unprotect it and found a way where I need to change the format to zip. The thing is, when I manage to open the sheet, it ended up corrupted (the formula couldn't work) so I wonder if any of you could help me to open my sheet.

Another question. I read on an article somewhere that a correct password is not working is actually common in certain version of excel. I wonder if this might be the case with my worksheet.

Thank you all for your help in advance. Have a nice day

Regards,
Nora