Rebounding From Injury

I am returning to cycling after I fractured (shattered) my pelvis in a mtb accident back in late April of this year. I was in a wheelchair for 2 months, on crutches for an additional month and started turning cranks again in mid July. I actually started feeling relatively good in mid August as I started feeling a little power creeping back into the legs. I have taken things pretty slowly and have listened to my body any time something doesn’t feel quite right. Lately I am becoming increasingly frustrated because my power seems stuck at a level about 30 watts below what it “should be” (240ish W vs 270ish W FTP) for the amount of training I’m doing. My injury feels pretty well healed now and I don’t feel I’m losing any power from that area. I just feel like my body isn’t adapting to the training stress in a general sense. I have mostly kept my training in the sweet spot area and below, but have gone into VO2 territory on a few group rides. I’m 45 years old and perhaps it is just taking me longer to recover because of my age. Are my recovery expectations just too high? Is it possible I will never get back to my prior fitness levels? Any insight is much appreciated.