In the absence of the problem being that you own and use a Mac, I would say you have routing or peerage issues occurring at the ISP level, from time to time I get the same thing happening. As people have rightly suggested, switching browsers and checking for plugin conflicts aside, you could try flushing your browser cache, or indeed re syncing your internet connection to see if it has any effect (power cycling the gateway I think they call it in the lingo). Checking your ISP's status page may indicate an outage or a known fault too although with peerage issues ISP's tend to obfuscate and hurl a lot of BS.
Over the last 3 or 4 days mensbiz has been as slow as buggery for me too, I'm in inner Sydney and I'm on an ADSL2+ connection around 300 metres from the exchange so I sit on a stable, relatively fast (downstream) connection.
Also, yes, FireFox with uBlock Origin & Disconnect me FTW.