Hi, to be honest I never really found a solution. I switched to a VPS, had them optimize as much as possible, installed and set up W3TC, added a CDN, and I’m still working on optimizing everything. I’m thinking about just sucking it up and hiring someone to take care of the loading issue. At least it’s no longer causing downtime.
Sorry, I wish I could give you an answer. Please let me know if you find out what’s going on.