Awhile back I migrated from GoDaddy webhosting (weathertiger.org, still up) to DreamPress managed wordpress webhosting with DreamHost (weathertiger.com), where I at first enjoyed the increased speed, but then ran into several issues with their caching (Varnish) and its lack of compatibility with the WPMUdev plugins I needed to use (specifically, Membership 2 Pro, Appointments+, Ultimate Branding). After consulting with WPMUdev support and DreamHost support, I decided to "downgrade" from DreamPress to managed VPS hosting with DreamHost, which seemed like a pretty painless process initially.
My website has been running incredibly slow ever since, and I've been trying to troubleshoot, using a combination of caching and optimization plug-ins (Hummingbird, WP Super Cache) and even setting up CDN through a DreamHost/CloudFlare partnership. I made some headway with this, getting down from 18 sec to 12 sec average load time, but it's been steadily climbing back up again.
Maybe DreamHost's automatic "downgrade" feature did something screwy--should I try to figure out how to wipe my VPS and get a fresh wordpress install? or should I just find a new host? I've read good things about DreamHost VPS elsewhere, but I have had nothing but trouble. I am also engaging with DreamHost's support, but it tends to be quite slow and unhelpful compared to WPMUdev, so I thought I'd try here in parallel.
I just tried switching to the default 2016 theme and disabling all of the plugins, and my load time is still 7-8 seconds. I've enabled support access in case it helps. Please advise me on what I might do next.