2022 Subaru Crosstrek Seats Problems

I was driving about 55 mph on a county highway and an animal appeared in the road. I hit the brakes suddenly, and my work bag containing my laptop and file folders that I had placed on the backseat behind my driver seat Flew forwards and hit the back of my seat. I felt the impact in my spine, And by the next morning I had moderate back pain moving and breathing as if my ribs were bruised. I can only imagine what would happen if I was going at a faster speed on the freeway (locally the speed limit is 70 mph, but people typically drive 80 mph). This morning my husband was just tapping on the backseat with his hands and I could feel everything while sitting in the front. I am disappointed in the car and afraid to put things in the back seat. I feel as if having a solid or semi solid barrier built inside the seat back would have been a no-brainer safety feature.