When will I be able to sleep on my back, sides, and regain flexibility after Lower Body Lift? (photos)

At 4 weeks post op, I still feel tightness and have swelling in my frontal abdomen area. Last week my surgeon gave me the ok to try to lie flat on my back, and I tried that for a few nights and couldn't find a comfortable position. I want to know when will I be able to lie flat on my back and sides, and also be able to walk faster and regain flexibility. My surgeon is amazing and told me that my body will let know. I just wish for a more average number post op of like how many weeks or months?