What Causes Dizziness Along With Constant Fatigue?

I am 42 years old. My periods has change in the past 5 months. From every 28 days now they are closer. Also, my periods are not that long, brown color and just few days. I have dizziness sometimes. I feel with no energy. My hands fall sleep really easy. Even if I m reading a book. Both hands at the same time. Doctors cannot tell what is going on and now they are sending me to a ostho doctor. I m confused. Any ideas?