hello anthony
about the script we need to know if the high cpu consumption is because of nginx or php, because both can be optimized, can you let us know about the php bottlenecks that your script generated.
If you want to analyze your server in depth, I recommend using netdata, it is easier to understand the script bottlenecks
the VPS service itself is not ideal, besides being expensive you are paying for a CPU and virtual memory, wouldn't it be better to hire a dedicated server for the same price?
if you want a recommendation, please visit this link: https://shorturl.at/byQSW is the best dedicated server provider in the world, Hivelocity