I agree with all the previous answers! My lymph node dissection (in April) hurt more than the mastectomy I ultimately had (in May). I did use a pillow - one that was longer and narrow - and slept on my back with my arm elevated on it. It helped until I could move around in my sleep more. I also had the numbness and it's still not 100% back to normal, but I am used to it, I think. It's a slow and sometimes painful recovery. Definitely get a referral for physical therapy. There are PT's who specialize in post-mastectomy.