Why do i still have PTSD ?

I was bullied severly in school for 6 ongoing years ... i was isolated, depressed, and had no confidence, i was obese as a result of comfort eating ... now im at college and had PTSD since in 2005 i got it on a bus .... i still have it ... im mostly over what happened ... i never have nightmares or ever did ... im sure it was the stress that did it ..... i have been to a psychologist before also .... i still experience depersonalisation constantly, the world is dreamy and spacey ... and i also have tinnitus ... what to do ?