Q: My MB Pro is frozen after el capitan download.  Even safe mode is no effect.  It completely shut down my Mac.  Your help is needed please...

My MB Pro is frozen after el capitan download.  Even safe mode is no effect.  It completely shut down my Mac, that I only get stuck in login screen which freezes halfway through.  El crapitan totally messed me up that I put my Pro down for months, but now I have returned to see if I can fix it.  I even tried reinstalling my osx from the disk, but nothing happens; after I select my disk, circle of death, then frozen white screen.  Yosemite was my last successful update. Your help is needed please...