Thanks for posting your query.
You state that you have been experiencing shaking during sleep for more than a year.
It is quite possible to get shivering when you are in stress, as it releases chemicals like epinephrine
which may cause shivering. On other hand it is also common with weak people who do not take adequate diet.
Try to get out of stress by exercising, meditation
, self hypnosis
and yoga.Take proper diet and sleep well.
I advise you to visit a doctor and get your thyroid
profile checked to rule out endocrinological causes.
Hope it helps.