I know a VPN does this, but I want a VPN / proxy type thing that only kicks in when I visit a certain website, and is not active when visiting other websites.
I remember using an extension like on Firefox (or maybe Opera) a few years ago, but I cant remember the name
Thanks 
Maybe SwitchOmega cloud meets your requirements. But it’s just a proxy tool, you need add proxy server by yourself
What’s blocking the website? Is it geoblocking? Is it blocking you based on your IP? Does the website still load but doesn’t let you do anything/shows a “blocked” page?
Hub vpn on chrome web store works and it’s an extension
I can recommend anyone to learn how to do this. I run Squid with simple authentication on a Raspberry Pi at home and it allows me to circumvent geoblocking for websites I regularly use when I’m traveling.
Blocked by government orders kind of deal. So the isp does the blocking. I reckon, not 100 percent sure
An error should display on the browser window when you try to load it, what is it?
For context it might be something that you don’t even need a tool for
What it shows is - “The connection has timed out”