If your heart stopped beating from the cold and you were revived, it might have some kind of long-term effects, possibly on your heart or maybe your brain. Or, despite how dramatic that incident was, it's possible you have a medical issue independent of it. One possibility is narcolepsy, the condition where people wake up many times in the night (without realizing it) and therefore are extremely sleep deprived, and fall asleep suddenly all through the day. You could certainly have anemia, it's especially common for women, but it's hard to assume it came from that event.
Do see your doctor, for sure. If you are focused particularly on anemia, you could test that at home by taking an iron tablet every day and seeing if things improve. (Take it with Vitamin C, for the best absorption.)