Is your Wordpress app connect to your MySQL app? I see you have that hosted with us as well.
The MySQL app is using all its available memory. As of about 4-5 hours ago (near the time of your post), there is no free memory available on the instance. This would slow down Wordpress considerably.
I’d try scaling the memory up a bit and see if the situation improves.
fly scale memory 1024 -a your-mysql-app-name
Edit: last 2 days chart of “memory available” metric. This is the memory that can be allocated (sometimes by freeing some other memory).
