Do a foundation year or do clearing? Worried about getting into uni in 2021.

Yes the Foundation Year would be ideal if you have a low grade, but better check with the Universities. If you are planning to go in 2021, you do not need to worry too much about getting from "Clearing". You would need to apply via UCAS (deadline date at around mid-January 2021) for the 2021 academic year. You can choose up to 5 choice. Before that, you would need to visit for the Open Day (or virtual Open Day) and talk to them.

By the way, BBC is very good grade and I am pretty sure you would get accepted straight into 1st year rather than starting at Foundation Year in ANY other Universities, but do you only want to attend top University like you mentioned (Newcastle)

People who has ITV grades, may even get 1st year entry too, but probably via Clearing (!)

https://www.theuniguide.co.uk/search/course?utf8=%E2%9C%93&c%5Bq%5D=architecture&c%5Bacademic_years%5D=2021&c%5Bsort%5D=relevance

Northumberland University (Newcastle) needs UCAS 136 points whereas Dundee only needs 104 points, depending on your choice and grades/

The Foundation Year is not actually linked with a university as I'll be doing it as The Northern School of Art (CCAD). They told me they would do the best they could to get me into a Russel Group uni, and I know getting into a RG isn't everything (I am looking at Northumbria) but it's just devastating that I might have my chances ruined because I've been downgraded . Obviously I know a lot of other students are in the same situation, and honestly I just wish the government would take action and fix this all.

I need some advice

It's always been my plan to go to one of the following universities to study Architecture: Newcastle, Glasgow School of Art or Edinburgh.
However, I did not get the grades I wanted at all and I cannot appeal because the mock results they used were the worst mocks I've ever sat. I was fully hoping for to get ABB, which was realistic- but instead I've been given BBC.

I have been planning to do an Art Foundation year since second year of college began, but I'm worried that if I don't do clearing now I won't be able to get into any the unis I actually want to because my grades are so bad. Will the foundation year even help me get onto this course? Or should I just look at clearing to do something else??

What I'm really worried about is universities not allowing special circumstances for 2021 like they did for this year. They will have a complete set of students who actually sat their exams so why would I even have a fighting chance with BBC? I really really do not know what to do.