I’m a writer rather than a designer but the first thing I noticed was that your gig title is really long. Try to be more concise - perhaps something like ‘I will turn your photo into a movie poster’. It’s easier to read when people are skimming.
Perhaps you could try using your most striking image for your main photo - maybe just an ‘after’ without the ‘before’ (the Turtles one is particularly cool IMO!).
Another good tip is stay online all of the time; I think this somehow boosts your visibility. You can do this by downloading the app, which keeps you constantly logged in.
Buyer requests are great - don’t only focus on exact matches to your gig. If you sell movie posters but can also design a flyer, do that, at least at the beginning. The more sales you get, the more sales you get - if that makes sense!
I would focus on Fiverr itself rather than advertising your Fiverr account outside, like on Instagram. Like someone else on here said, most of your followers won’t use Fiverr. By all means, include your link in your bio and post images but don’t rely on that as a way of getting gigs.
Use keywords in your description and make use of your tags. Just basic SEO - a keyword in your title then 3+ of the same one in your description. Then different relevant ones in your tags.
Finally, don’t increase what you offer for $5. I’m from the UK too and I agree with you - it’s true that you can’t offer the world for $5 and one movie poster for $5 is perfectly reasonable. I charge more than some and I don’t find it puts people off at all. It may even inspire confidence in your service.
I hope this helps! Good luck