2014 Mazda 3 rear shock problem

Everytime I go over a pot hole or sewer grate the car makes a hell of a noise. I’ve since stopped using it and have an appt for Monday. Anyone know how much damage cost I’m looking at and what the issue is?

I have attached some photos. Seems like that strut behind the rear passenger side tire is loose and I’m able to move it with my hand.

Thanks for any info.