How did you cure your DSPD? I am asking for a friend..:P
I still sleep weird times but at least I'm no longer laying there frustrated and extremely stressed at 5am that after laying there for 5 hours I'm not asleep and worried about oversleeping or just having to go to work without sleep to not risk being scolded about showing up late again.
One day around age 26 it just went away after having been a problem since early high school. No clue why. If you're still young, your "problem" may simply be youth.