How to minimize forgetfulness and disturbed sleep?

Hi doctor,

For a while, my memory has been really bad. A recent event with my memory is as follows. My alarm goes off at 7:04 AM and I looked at my clock at 7:05 AM and I could not remember how my alarm had gone off, which was only a minute later. But, things I memorized before some years are still remain in my head. For example, as a hobby, I learnt mathematical pi, I can still recite it. But, I have forgotten some numbers and I am frequently mixing things up. Another thing that has happened is that I cannot sleep at nights. I have to leave the window open and wrapped in several blankets to sleep, because either I feel too hot or too cold where in a split second I am either sweating or shivering. I also get massive waves of heat or cold. My hands and feet normally go cold and numb during my cold episodes and when I get hot, I feel dizzy and nauseous. I feel distressed. I generally see myself as a person who barely eats or drinks, but for the past month I have been drinking three times more than usual and eating full, but healthy meals. I would just like to know if there is a diagnosis or at least some steps that I can take to minimize this. Thank you.