[ERROR] DKIM record no longer good. We will stop signing your emails with DKIM at the end of the warning period if not fixed.

I recently pointed a Go Daddy domain at a new Squarespace site and somehow, in doing so, broke my email which is housed with Protonmail. MX is in there, but I think it may be the SPF/DKIM and I am out of my depth here. 

Is anyone on here who can help?

Thank you!