Ah sleepingflat on your back is just as bad- week 2&3 were terrible for back and sleep problems for me. I would wake up with agonising pain in boobs and terrible back. I found elevating my legs/thigh high (I used couple of pillows) helped. It does get better though-I was a ‘fetal position’ sleeper pre op, and now love sleeping on my back. 6weeks post op.