Try different positions? If you feel uncomfortable sleeping on your left, then turn to your right, if you still uncomfortable, try sleep sitting up at an angle propped by pillows on your back.
I am late 2nd trimester too and have the same problem as you, and not only do I get belly cramps, I get ribcage pain as well, sometimes my organs hurt too😢. Anyways now I have 3 big pillows and 2 tiny pillows on the bed 🤣🤣🤣. One for laying flat on my sides and 2 for propping myself up to sleep, the tiny pillows for my tummy and back when I lay down. I have a bolster too for whatever purposes I need. Ill often wake up in the night to shift position. My poor husband has been reduced to sleeping 1/3 of the bed for now haha.