I took a look at your VPS, and it is indeed very slow. This is because MariaDB and PHP-8.3 are using all your memory, and your load is very high. Between MariaDB and PHP-8.3 they are using 3081 MB of memory and your VPS only has 2048 MB memory, and the OS and everything else needs to have some memory to operate too. When I checked you only have 300 MB free, and 1.4 GB is swapped. You should aim to have only 0-50 MB swapped, and definitely more free memory than only 300 MB. Here are some options to increase the speed of your VPS:
I would recommend increasing your memory to 3 GB or 4 GB at https://heliohost.org/dashboard/upgrade/
You could modify the MariaDB config to use less memory if you don't want to upgrade the memory.
You could modify the PHP-8.3 config to use less memory and/or have less FPM workers if you don't want to upgrade the memory.
In order to free up some memory for you, I restarted MariaDB, but it will likely just swell back up to the same memory usage as before unless you modify the MariaDB config as I suggested in option 2.