Administrator Can’t access Dashboard menu

Hi all,
I am one of the users who have administrator access to our business website. All of a sudden I am unable to access anything in the dashboard menu. I can login, but cannot do anything else. I cannot even access my profile; I am constantly redirected to the login page. When I DO login it takes me to a /my-booking/ page and I cannot get anywhere else.
I have tried clearing the cache, different browsers, different OS, different devices, mobile and broadband internet connections. Absolutely nothing works on my end.
The odd thing is, I can access everything when I’m using my boss’s computer at the office (I work remotely at the moment). I can log in, access the dashboard menu, make changes etc. I tried resetting my password and demoting my access to no avail.

I will be eternally grateful for any help with this. I am unable to do my job without this access.

Many thanks in advance!
Sarah

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