What to do if there’s hard leg and vibrations in the car?

Hy, have a V70 year 11/99 2.4T Autom. 210000km Since about half a year, the car has become hard as a leg, as if I had a hard chassis or something built in. If dampers get old, the box becomes soft like a mustard, what can be when the suddenly is so hard? I have the original chassis inside, back with the standard SACHS Nivomatic. I also have vibrations for some time, almost always, this is a bit stronger when braking. The wheels were re-engineered, and now also the same thing with newly washed and re-fitted winter bikes. Brake discs have already been replaced twice, so that can’t be the same…. Steering rods have only been renewed a year ago. I think of the cross handlebars? But why is he car so hard? Deeper is he also not standing there, than otherwise, because he thought the dampers are there, and let through or so? Was at ATU a damper test, where was it so gratefully dropped from the 20cm?