Long wait time

Your site was super quick when I tried it just now.

Try this service:
https://dnslytics.com/reverse-ip
and enter your domain name.

Its showing that you are sharing your hosting server with 719 other sites. Quite a lot. When some of them are busy your site will be in a queue for server resources.

I have also come across an instance of where another site was running an unauthorised resource-hungry script.

Either way, I should take the problem to your host’s support service. Explain you are not happy with the wait times. Ask them to check if another site on your server is taking too much server resource. Ask if they have a better server for your site, ie more powerful and/or with less other sites on it.

Ultimately, you may need to try another host. Unfortunately, there doesn’t seem to be a way ranking hosts by server resources. Generally many of us choose a service based on price so the hosting companies will cram as many sites onto one server as they can to be able to keep the price low.