2007 Honda CRV back tires getting very noisy

Tires and Wheels problem
2007 Honda CRV 4 cyl Two Wheel Drive Automatic

My tires are 3 months old. They are gettting very noisy. I found also that the tread is not equal anymore. Look like both tires at the back are jumping up & dow while I am driving
i have 51000 miles on the car. I cannot believe my suspension is bad already, I never did loaded the back with anything or towing a trailer.
Who can help me?
Thank you