Hello and welcome to the community forum
I am not an expert at unbricking but everything I know points to the necessity of FP doing that for you.
Do you have any relatives/friends in Europe that you could post your device to?
As far as I understood, the US support is limited to people who purchased their devices from FP in US.
Edited to add forum guidelines on reaching support, ✏ The Forum Guide to... Fairphone Support