They won’t recover, that’s not how trade works.
1. Irish border and Good Friday agreement
2. EU Citizens rights in UK
3. Payment of billions to which previous UK governments signed up to as EU member
4. How will you ensure low quality food from US does not enter EU"
Just like Russia could say "no gas for you" if you make too much of a fuss about what happened in Crimea.
Now if the UK's view of its own future diverges from the EU, it's totally normal to see complications appear during negotiations.
Canada had to adjust their immigration policy for several EU countries to get CETA. The UK will be over a barrel and will have to make major concessions.
Whether you're pro EU or not this situation is a total balls-up.
Hard to imagine a good outcome.