Accidentally froze my fresh mussels
Freezing live mussels is generally not recommended for long term storage, but if you plan to eat them in the near term it is not a problem.  The issue that I can see is that freezing kills the mussel.  So, unless you sorted them beforehand it will not be possible to tell if any were dead to begin with.  If it were me, at this point, I would sort through them and remove any with broken or empty shells and cook them up.