Sadie, it sounds like you are healing very quickly. That's some major surgery, affecting the body core, with a huge impact on a person. Strength will return over the next few months, so don't try to be an overacheiver in the next few weeks. Just let yourself heal up.
Sleep is good, and being able to roll onto your stomach, wonderful. (I had bladder surgery several years back. Similar impact to GCS, but a less interesting, if useful outcome. But 3 weeks with a Foley catheter! Ow.)
Take care, now!