[HELP] All normal visitors are required to enter user/pass to access a page

Hi,
In last few weeks I saw hundreds of hack/login attempts on my website so people suggest me to password protect my wp-admin folder and restrict it to only my IP address too.

After I protected my wp-admin folder the website’s behavior changed, now it is asking from my normal visitors to enter user/pass to access page on my website. They’re complaining about “Authentication required” popup every time they open a new page and they’ve to cancel it on every page in order to access any page.

And I want to know what’s the best way to limit login access to only my IP address. I have Google that and stumbled-upon three different ways/snippets to limit access and I don’t know which one is correct/recommended.

P.S
It is displaying the “Authentication required” popup whenever I visit /wp-admin folder which means that the snippet I added on .htaccess file is correct?