My gig was on the first page, suddenly my gig went to the number five page. Now how can I bring it back to the first page.
Deliver high quality work that earns positive reviews. Fiverr likes sellers that prove themselves, bring in steady revenue, and take responsibility for their own success. If you do these things, you might find your way back onto the first page of the search results.
Please keep in mind too, you neither deserve to be on the first page of search results, nor should you be there just because you want visibility. If you want to be seen, you are going to have to earn that right.