Ur still too early u should be fine sleeping on ur back. It's when the baby is much bigger that he can block the artery
I think a body pillow will help, I am also on my second and I have trouble getting comfortable at night but the body pillow helps me out alot.. i used to wake up not feeling one side of my hip
I slept on my back most of my first pregnancy. Even if I went to sleep on my side I ended up on my back. Just be carefully and watch for signs of sciatic nerve issues or loss of circulation anywhere.
Oh and a pillow between your legs should help your hips :)
You're still early on so I doubt it's horrible for you to sleep on your back now. Once the baby is bigger than you should avoid it. But honestly I'm 37 weeks and I just can't sleep on my left side anymore I roll over on it anytime I wake up but on my right side or on my back but slightly tilted is most comfy!
Maybe try a pregnancy pillow or a body pillow or just some pillows behind you so you're not completely on your back! :)