I'm a back sleeper too, I read that I should start sidev sleeping early so I can get used to it by later trimesters, but it really isn't as simple. I'm third Tri now and sleeping on my side more, I find hugging a big soft pillow and having a bolster to lie my back against (so even if backsleep I'm slightly angled) helps. Some nights if I wake up 4am I still can't go into deep sleep on my side and just drift, but I feel sufficiently rested. Good luck!