massive VAT mess, any ideas how to fix it?

Hey everyone, looking for some advice because I’ve landed myself in a massive VAT mess.

I’m VAT registered in France, and I signed up for Amazon’s Remote Fulfillment program. I (wrongly) assumed that since my inventory ships from FR, I was safe. Well, turns out Amazon has been storing customer returns in warehouses across Germany, the UK, etc.

Now, Amazon is demanding VAT numbers for every single one of those countries.

Has anyone dealt with this “accidental” nexus before? Is there a way to fix this without spending a fortune on back-dated filings, or am I looking at a total disaster? Any tips on how to handle the Amazon compliance team would be a lifesaver.