I have Insomnia after a TT/Breast Reduction 10 days post-op, what is causing this?

I have not slept more than 4 hours in the past two nights. The first night it was from restless arm/leg, which was starting to occur before surgery, and last night, very tired but couldn’t fall asleep - I don’t know if I’m on guard, tired of the back position or what. I’m 11 Days from a TT and Breast Reduction. I have sensitivity and some mild discomfort and the drains are still in, but no bad pain.