crossed out symbol instead of an apple during start up

Start ups have been getting slower and slower for me and now I can't even get past the white screen. I now have a crossed out symbol instead of an apple during start up and the wheel is just spinning. I tried to start it up in safe mode and this is what I get. Even if I get to the login screen, things are frozen and I can't entrer my credentials either with mouse or keyboard. Typing this in from a PC. Yikes! Help!