how can i recover this rank ?

I've seen this posted a few times. So many people cheap out on tools like Semrush or ahrefs - It's literally your #1 tool. I use it for hours a day, researching my competitors and, better yet, tracking my keywords. You can see your fall keywords within 24 hours and make adjustments where needed.

I'd recommend looking at what keywords you were ranking for and the pages, from there look at possibly refreshing the content on those pages.

There are ways to recover but without details it's impossible to give advice.

Search the forum.

In 90% of the cases, you either have to clean up your link profile, improve content or both.