Hi and welcome to HCM.
It doest seems like something serious because rib fracture
cant be caused by such mechanism. Probably this is just a contusion
of thoracal skin and pain should pass in 2-3 days. Try not to cough
or sneeze, dont breathe shallow,breathe properly and take some of the standard painkillers. ALso sleep with elevated upper body. If you experience breathing difficulties or dizziness
you should visit doctor.
WIsh you good health.