I am a student , 18 years old and lot into meditation and chanting , I do not have any trouble in focusing or emptying mind . Only problem is while doing yoga nidra i loose consciousness after some time , i was not able to keep track when i actually dose off but i feel its probably after 30 mins or 50 min , i tried multiple things to try not to dose of ,, even started sleeping in lord vishnu sleeping pose so that my legs dont get numb and i felt lying down is too much comfort and maybe thats why i sleep in middle and sitting in meditating position is too much unconformtable thats its hard to rest , what should i do ?