NO wordpress pages loading on my computer

Hi there,

I need some detective help here.
I am not able to load my website on my imac so firstly I thought there was an issue with my page.
However I have now established that no wordpress pages AT ALL are loading on my computer.
They come up with following error:
This site can’t be reachedwww.selfcatered-saintmartin.com unexpectedly closed the connection. ERR_CONNECTION_CLOSED

Important to say is following:
I have tried connecting to a different network which makes no difference.
I have tried different browsers (chrome, firefox, safari)
I have tried logging into different users.
I have cleared cache etc.
I have tried private windows….

No luck at all – Same error message!
And I just figured out that no sites that are built with WordPress are working at all. Very strange! Are they being blocked by my computer? How? What do all WP pages have in common?

I cannot log into the WP dashboard either.
HOWEVER I can see the page and log into dashboard on any other device (such as mobile / macbook) even if I am using the same network.

– – – – –
How did it all start?

I was working on a new page on my site which is currently saved as draft.
I am not sure what exactly I was doing but a error message came up which I clicked ‘whitelist action’ (I am pretty sure! These messages pop up regularly and my webdesigner did say that’s what I should do.)
I should have read the message and given it more attention … However I clicked it quickly like I had done loads of time before. Just this time it obviously did something to it which now makes my computer not load ANY wordpress page at all.

– – – – –
What’s even more strange?

My colleague who works from our office in France has exactly the same problem!
She was logged into the dashboard at the same time! But from her laptop in France!
She now has the exact same problem.

Please, is there anybody that can help?

Thank you!

The page I need help with: [log in to see the link]