What is this hanging down

 

That is the cut wire harness of the secondary oxygen sensor.

 

Can I drive it like that at least to get it home or no?

 

You should be able to drive it like that to get home. Sometimes a fuse may get blown from a short in the wiring though.

The missing cat will cause it to be loud and it may drive rough without adequate exhaust back pressure.

 

Ok thank you