How to protect sheet

Realistically, no, not without a lot of effort. Unless you buy a third party application designed to "secure/encrypt" your workbook. There are several about but none get a particularly good write up (at least, when I last looked).

Any "security" provided by Excel itself ... workbook protection, sheet protection, locked cells, hidden formulae, rows, columns, sheets, etc., requires a macro enabled workbook and, quite honestly, isn't worth the code it is written in.

If you simply want to ensure that only you can use it on your computer, probably the most secure method is the Windows/Office Password to Open/Password to Edit with Read-Only recommended. Use long (but memorable to you) passwords with upper case, lower case, numbers and special characters.

I think that even professional, paid for password removal applications will struggle to some extent.

It all depends on the value of the content and the Intellectual Property.

Regards, TMS