This maybe my first post but i am an expert with linux so i used some of my abilities to boot mac when it wouldn't boot (would shut down while booting)

1. Boot into single user mode
2. type /sbin/fsck -fy
3. type /sbin/mount -uw /
4. type exit
5. tada you are booted into osx

this is how i boot after i deleted the first ever acc. made on my macbook pro. so if anybody can help me boot normal, it would be appreciated