why can i only visit 50% of websites?
 

I can't access gmail.com, paypal.com, escrow.com and a ton of other sites... what is going on with my ISP? anybody know what this could be caused by?

Could be you are getting a fucked up connection. That or your dns servers are fucked. Use diffrent dns and see if that helps.

Turn off the proxy as well.

If you use a router, try resetting it

check your hosts file.. some spyware could have corrupted it.. windows/system32/drivers/etc/hosts