Thanks, that’s great. Somehow you have swappiness set to zero , which is almost certainly most of your problem.
But there are three settings worth getting right: one is swappiness and two of them are mentioned in MKJ’s Opinionated Discourse Deployment Configuration
/proc/sys/vm/overcommit_memory
/sys/kernel/mm/transparent_hugepage/enabled
/proc/sys/vm/swappiness
You can set these once, but you should also ensure they are set at boot time - see MJK’s post, and check those files before you overwrite them.
I suspect something is happening at boot time to set the swappiness to zero. Possibly your hosting provider is trying to discourage swapping to SSD. But you must have swap, or else you must upgrade to 4G RAM at least.
Perhaps try
egrep -r swappiness /etc/
to try to find where it is being set.
There is advice elsewhere on this forum to set swappiness to 10 - I prefer to leave it at the default of 60.