Welcome to HCM. Nightmares can be caused due to sleep deprivation
, sleep disorders, tension, depression, anxiety, stress, post traumatic stress
disorders. It can also occur due to intake of some medications, drugs, narcotics,etc.
Don't worry, it is the first time it happened to you. Just stop taking any drugs, alcohol that may trigger nightmares and cause you restlessness
. Avoid taking snacks late night as it has the tendency to increase metabolism and activate the brain cells and neuro transmeters.
Try to sleep on a comfortable mattress. Read or watch a comedy movie before you sleep. yoga, exercises and meditation
will be helpful for you. If still you have nightmares you should see a counselor/ psychiatrist
. Take care.