22 hours is far more than I oversleep but I lose several hours a day. I thought of narcolepsy and other problems and will ask a doctor next week. If he can help I will put it on the forum for you. Take care of yourself
Causes of excessive sleepiness are sleep-wake cycle disorder like in night shifts, sleep apnea and other sleep-related breathing disorders, psychiatric disorders like depression and schizophrenia,diabetes,obesity,restless leg syndrome,use of drugs or alcohol and narcolepsy(Abnormal sleep disorder leading to excessive daytime drowsiness).
You should consult a sleep specialist and get all these causes ruled out.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.