Brain sleeping while awake? Brain trip?

Hello,

I have had this a month or two ago and i had it last night again. When i'm in bed and very tired my brain sometimes trips out. I learned this happens when i have slept little the previous day. When i experience this my mind has trouble grasping proportions, for example my bed felt the size of a football pitch, my body feels out of proportion aswell. From feeling very tiny to bloated and round in a few seconds.

Also if i imagined a picture in my head the image would shake, fly all over the place, 1 second it seems normal size then an intense zooming out. In a sense i felt out of body, also remember flying real fast trough something, like made up non logical scenery.

All this whilst still being awake. I wonder if someone knows what it is or experiences it also.