What have I done?

[Yaris1234]

Hello. I have a 2005 Yaris. I suspected a bad wheel bearing and thought about lifting up the car with help from a jack. I placed myself on the left hand side at the front and placed the jack under (from what I thought was a strong point in the construction) a circular little point (picture). I started to pump and the car lifted slowly. Something didn't feel right so I lowered the car back down to the ground. I looked under where the jack had been and saw that I had made a big dent, going right up, close where the drivers left foot is placed.

I think I have hurt some kind of soft metal, as you can see from the pictures there are cracks along the circular "thing?" also a bit along side on the first picture to the upper right (red marking). Have I breached something serious? I guess I don't want moisture traveling up there through the cracks...?

Please help me sort out what I have done and how serious this is.