Sometimes lack of sleep or extreme fatigue is linked to hormonal changes like thyroid fluctuations. Keep sharing your sleep issues with your doctor in your regular checkups.
With twins, finding a comfortable position was a project! Use a pregnancy pillow or just pile up 4-5 normal pillows around you, it seriously saves your back.
I literally just delivered last month and trust me, left side sleeping with a pillow between knees is the only thing that worked. Don't drink too much water right before bed or you'll run to the washroom all night.
Meri saas suggested drinking warm milk with a little kesar before sleeping, and honestly, it really helps to relax. Also, keep a pillow under your tummy for support.