Wordpress (fresh install) site not loading in/very slow

I signed up for the $5 droplet plan for a wordpress site. Fresh install, only plugins are Yoast so far. The theme is one of the default ones (twenty-21). Sometimes, I can get into the website and everything works normally.

Lately, a lot of the times, the page just hangs while loading. I’ll often be sent to this wordpress page:

Error reconnecting to the database This means that we lost contact with the database server at localhost. This could mean your host’s database server is down.

Are you sure the database server is running? Are you sure the database server is not under particularly heavy load? If you’re unsure what these terms mean you should probably contact your host. If you still need help you can always visit the WordPress Support Forums.

I’ll try on my phone with a data connection (not using my home wifi), and it won’t even recognize the domain sometimes (sends me to default AT&T search for my domain name).

I know I set my domain up correctly, because it does work sometimes. I just have to wait 10-20 minutes or so, and the website will work again for another 10-20 minutes.