It could be a few things...
1: Perhaps your service is very niche without too much search volume. You can check your impressions on the "gig performance" section under "active gigs".
2: Check your order completion, delivery and response rates to see if they're top notch
3: How are your competitors doing? If they're lagging behind too, then you know it's probably a demand-disruption issue.
4: Try getting Fiverr Plus for a month and see if an exec can troubleshoot this for you.
Lastly, never lose hope. All will be well!