Can it cost you the match altogether? Or is there any hope left if you could do well in other steps? I'm talking about a visa needing IMG :(!!!!!!

Did you fail it or are you expecting that you may fail it?
I've heard the fail rate is very, very low, and the main objective is to see if patients can understand your English.
Don't worry too much if you've not taken it yet. Give it your best try. Speak clearly and loud enough during the exam. If English is not your first language, perhaps practice with someone who is a native English speaker.