How important the right pillow is..

How important the right pillow is. Because I cannot lay flat physically, I bought a pillow from a specialty bed store and bought this pillow that makes me sit upright as much as possible.
I also have a problem of waking up from a deep sleep and start flying spinning... So ,my husband discovered that my problem was positional. Once I started using the pillow the night spins were reduced. I still get 1-2 a month. They are awful. I hang on to my husband for dear life ,often falling out of bed when it stops I am panting Ike a dog , my heart is pounding, and I often go fetal for at east a hour before I can get up.... Then I spin in bed for awhile before I can go back to sleep.
Then the next day I fee depressed,worried about the next night