Is there something wrong with my nerves in my brain?

When I lay down to go to sleep on my back I start to feel this weird fuzzy relax feeling from head to toes back up and then I feel like my body/spirt is shifting or spinning and I drift in and out into dream state .sometimes in class or anywear I get that same feeling my body feels relaxed and feels like am floating and my body is vibrating but i get giggaly and loopy.plz help I'm 16i don't do drugs is it a nerve thing