Cannot erase authorization

Hi community - I am a student at a local college and had to get a new laptop as my other one broke. When i did i keep getting an "activation error". From the help chats i know i have to erase authorization and then log back in. However, my school email which i used to sign up is not recognized as an account, and i cant remember my password. there seems to be no way for me to reset this and i cant access my textbooks. i have tried to uninstall and reinstall but it remembers me but still wont get me authorization. 

Thanks in advance for all your help