connected to internet but cannot load pages from browsers

Error 118 (net::ERR_CONNECTION_TIMED_OUT): The operation timed out.

I have been getting this error message all day, everytime I try to connect to the internet. Sometimes if I persist I keep hitting refresh I'll get through eg to Majorgeeks it took 2 1/2 hrs tonight. (However then when I typed the message, and sent it, it timed out and the message deleted - I am writing this 2 days later, because I fluked a connection).
I have 3 computers - 2 Windows, 1 MacBook Air, 2 iPads, iPhone- it is the same with everyone. I have changed my wireless router - no difference.
I have talked to my ISP - and the ping report was good, as was the Speed Test.
I have tried on Safari, Google Chrome, Firefox and Yahoo - no difference.
I can connect ok to the browser, but when I type in or click on an address I get this message.
This started last week and I think it has gotten worse (or I have just realised how bad it is because I was trying all day to work out what was wrong).

Please help me...I am getting so depressed and frustrated.

 

I think I have solved it. After going to MacDonalds and using their free internet I realised the computer was working fine. So back home I rang my ISP for the 4th time and this guy seemed to know what he was doing and didn't give me shit about a possible virus on all the pcs etc. He changed a couple of settings his end, and it seems to be working now. (just wish I could get the last 4 days of my life back).