I have a droplet on Digital Ocean and it becomes really slow some times when I have 30-40+ users at the same time. I don't know if its the droplets capacity or my code I didn't optimise well, but it's starting to become annoying. Are there any tips to inscrease the speed of my droplet?

Here's my droplet configs:

What can I do? Should I transfer on another hosting service? Is there any configs or options I can edit or add to my droplet to increase my server's speed?

EDIT:

Sorry, I should've specified what is it my droplet is running! I'm actually running a Laravel 5.8 app with a MySQL database. I did my own multi-tenants system so people can have their own version of my app (ex.: People can create leagues that will create a database for each league, and every leagues are independant).

I'm not familiar with all of that, but when I do the htop command on my server I get this, I believe there is one mysqld process for each league (database) on my web app.