Not much you can do to get it back, however you should contact Now and ask about the automatic compensation which you should receive should the internet be down for 48 hours or more
see here:
https://www.ispreview.co.uk/index.php/2019/03/automatic-compensation-goes-live-for-uk-broadband-isp-...
and here: https://www.ispreview.co.uk/index.php/2024/04/ofcom-raise-automatic-compensation-payouts-for-uk-broa...
My understanding is you may need to report the lack of internet connectivity to get the ball rolling and keep a record of your call, call again if not working by this afternoon, again tomorrow morning and again after 48 hours , making sure to mention the Ofcom compensation scheme .
In the meantime, i would also check to see if Sky broadband is down in your area, and / or other services are also down - sky broadband service status, downdetector and local ( ie spotted) facebook groups.
If you tether from your mobile and you have unlimited or a high data allowance then you should be OK in the short term, if i remember correctly 1080p streaming can use about 1.5GB/hour of data, make sure your phone is plugged in and has good ventilation as hotspoting can gobble up the battery and make your device warm/hot
