I have no advice besides what others have said. Try to do the re-learning of moving your bedtime forward or backward an hour or so every few days until you, hopefully, get to the place you need to be.
Perhaps an occasional hypnotic (Ambien, Chloral Hydrate, Dalmane) could help you get at least 5 or 6 hours of sleep, good REM sleep, deep sleep.
Oh, BTW, you don't have to tell anyone you are taking meds (if you are taking any). As long as you are functioning, it is no one's business - not the school's, not an employer's. Just don't talk it about it EVER to anyone, especially at work. Your secrets with quickly become fodder for gossip all over the school or job. I mean it - not a single word to friend, foe, boss, peer, anyone.
Warm bath? Warm milk? Yoga or other meditation/relaxation/breathing techniques? Total darkness, phone totally off, doorbell disconnected.
I wish you the very best.