On planes i feel/see the plane spinning if i move my head around. also happens when i blow my nose, sometimes just light headed meclizine doesn't help?

Vertigo: You are describing symptoms of positional vertigo. I have a feeling that the dosage of Meclizine you are taking is inadequate. You need to take on regular and sustained basis and not "as needed". Additionally the dosage should be escalated gradually to as much as 50 mg 4 or even 5 times/day before calling it ineffective. Some patients need such high dosages.

Labyrinthine disturb: You are sensitive to movement and pressure changes (inner and middle ear) MRI to rule out tumor or destructive pathology and symptomatic treatment.