I've experienced something like that, waves of anxiety or sudden terror while asleep.

Do you experience really restless legs during this? If so, lots of info online about restless leg syndrome, and I think there are even meds just for that.

Do you drink coffee or have other forms of caffeine during the day? It can affect us even hours later.

You could look over your bedroom, think on whether you need things cooler or warmer, what blankets and pillows are best, if you need to block out more light, anything like that.

You can find good articles online about nightmares and night terrors and other sleep disorders. You can sort out what diagnosis might fit then talk with your doctor, some meds might help. Also you can look into sleep apnea possibilities.

I've found that being too wound up before sleep makes for a restless night, TV and computer need to be off for awhile before I crawl into bed.

Good luck!
Sarah