My doctor said that under no circumstances should I sleep on my back. …

My doctor said that under no circumstances should I sleep on my back. Only on my left or right side. Even online they say that lying on your back the uterus presses on the vena cava and this negatively affects the condition of the mother and the baby. It can even cause losing the baby. I've been sleeping on my sides for five days and it's unbearably uncomfortable—everything goes numb and hurts. Is anyone else like me? How do you cope?