I Have Been Having These Weird Spells That Last About

i have been having these weird spells that last about 3 days. My body just pulls me into a heavy sleep. I can feel it just pulls me so hard and like sometimes i think Hey i wana move my arm beforeI fall asleep but its too late I cant move anymore I try to stay awake long enough to tell my mom whats happening but I cant stay awake long enough. I also dream constantly Just thousands of dreams. And like i said it lasts for 2-3 days Do you know whats wrong?