Unfortunately if database is corrupted there isn't any mid way to get out of this unless you have followed proper disaster recovery steps.
& I think database restored was unsuccessful that's the reason you aren't able to login into the SEPM.
I would suggest to do a fresh install and restore the communication by choosing one of the available option.
It seems you need to manualy create policies again.
I am not able to understand why you are restoring database? Because not able to login? or Moved SEPM to another machine?