my site refuses to work

https://aws.amazon.com/premiumsupport/knowledge-center/ec2-instance-hosting-unresponsive-website/

Also is it a single EC2 machine or are you using an Auto Scaling Group with an Application Load Balancer in front? If not, I would recommend doing so

https://docs.aws.amazon.com/autoscaling/ec2/userguide/what-is-amazon-ec2-auto-scaling.html

https://docs.aws.amazon.com/elasticloadbalancing/latest/application/introduction.html

Also if you haven't read this, it is recommended to go through this - https://docs.aws.amazon.com/whitepapers/latest/best-practices-wordpress/best-practices-wordpress.pdf