High CPU usage in AWS Lightsail and error to connect database in Wordpress

I just moved my site to AWS, but I’m having a lot of server issues. Every now and then it appears to me that he has problems with the connection to the database. Reviewed AWS I noticed it has a high CPU consumption, and I don’t know if that’s the reason. I would like an AWS expert to help me find the solution and optimize my server. https://share.cleanshot.com/ZYVxnwdD