Startup problems HELP PLEASE!

Hey,

My computer got frozen and i restarted it manually. After that i went on another thread that told me to restart Using command-s which didnt let me input any prompts and just kept showing me a black screen and never ending messages that looked all the same. That went on for an hour, for which i turned it off after it didnt do anything.. Now it is just a white screen when i boot and nothing works now.. I reset the pram but nothing happened.. Do i need to have it repaired? Will the hdd get erased?