Can fat tranfer/BBL get damaged by sitting on BBL pillow 6 weeks post op to drive? (photo)

I had surgery 6 weeks ago and I haven't sat yet not even to go to the bathroom, until yesterday when I went to drive to a friends house and go get my nails done... I didn't sit longer than half an hour everytime I sat down. I had fat transferred to my but hips and my thighs underneath my butt as well. Today my thigh underneath my butt on the left side looks misshapen and lumpy. Did I kill off the fat that was transferred there ? How could this happen 6 weeks out ?