Shut Down Twice due to excessive virual memory usage

Hello!

I’ve recently started receiving a large amount of traffic on my website TruTower, and last week the website stopped responding with a 500 internal server error. I proceeded to call my hosting provider and they informed me that my virtual memory allotment has been exceeded. They doubled the memory and I attempted to lower the memory using WP Super Cache. This morning, it happened again. I have since uninstalled WP Super Cache and added W3 Total Cache in its place, as I’ve heard it is more effective.

Here’s my problem: I downloaded a plugin called Memory Viewer in an attempt to troubleshoot the high usage and discovered that queries on my pages are running anywhere from 26-30 MBs. I’ve heard it should be closer to 20 MBs (although I’m not sure how accurate that is).

Does anyone know of a good way I can find out what’s causing the high usage (if it is indeed exceedingly high)? Timing is important, as my host has stated they may not be able to increase my virtual memory limit again.

Thanks!