you have got a blunt injury
to your eye.
blunt injury can affect any part pf your eye.
in your case like you mentioned you have got blood stained cornea
i would also suggest the same thing which your doctor is telling you to,let the blood get cleared and inflammation once settled down then cataract surgery
should be done.
don't worry things will settle with time,have patience.
please wear protective glasses hence forth to prevent injury to your eye.
hope this helps