If I sleep on my back.
Eventually everyone has it once, mostly.
Can you easily snap out of it?
Yes, realize it's a dream, calm down and try to move your palms and feet.
I get sleep paralysis 1/2 of the time I tend to wake up but it only takes me one minute or 2 to snap out of it(maybe It's more but I don't remember the rest)and snapping out of it is such a nightmare.
Should I see a doctor?
Just don't sleep on your back, and don't let any sort of pressure on your chest, even you hands, see if that changes anything.
And if you absolutely must do it, like a lot of people, make sure your spine isn't completely straight, like if you were using 2-3 pillows- I found that out after searching a lot on the internet.
That being said, when you think about whatever nightmare you had, and try to corelate the elements in it with what you saw thought about during the day or past, it's obvious they're merely a result of your mind. Doesn't mean there couldn
t be another explanation though, but in my experience this is it.