Quarantine regulations for travel USA > UK at present?

I have a family emergency back in the UK, and need to travel there from NYC (Green Card resident) early next week.
what are my quarantine regulations and requirements?

It's very confusing, so thanks for any help.

14 days quarantine on arrival I am pretty sure of

Not sure re anything else

Sorry to hear about the family emergency - unfortunately the best advice remains the (sometimes impenetrable) government website at https://www.gov.uk/government/publications/coronavirus-covid-19-how-to-self-isolate-when-you-travel-to-the-uk/coronavirus-covid-19-how-to-self-isolate-when-you-travel-to-the-uk .... there is a small chance that if you contact the US Embassy in London they could give you some more specific advice for your personal situation as they will be regularly getting such queries directly or via other US Embassies (as the quarantine rules are NOT based on your Nationality but based on where you are travelling into the UK from, so the US Embassy in London will be the 'experts' on US to UK travel assuming it is England you are needing to get into).

Best of luck!

Thank you both.

I'm a UK national living in NYC, so it seems will have to do the quarantine or some version of it.

Sadly New Yorkers will be judged by the same stick as the rest of USA, where they failed and have near endemic caseload, here in NYC we buckled down and quarantined hard to crush it. Very low prevalence now. Better than the UK and most of Europe.

I have friends in the fashion world and at their 'shoots' it is now common to have instant testing on site, so I'll see if I can get one of those on arrival, for some kind of personal awareness, even if it means little to les authorities..!