It really just depends what you mean by "fail".
Last year, you were able to lose a total of 82 marks and still get a 5 (for edexcel foundation). To lost 82 marks over three papers is actually pretty hard, considering each paper is 80 marks in itself. This year it'll probably go up by 5-10 marks, so let's say you can lose 75 marks and still get a 5 (THIS IS JUST MY ESTIMATION PLEASE TAKE IT VERY LIGHTLY)
So if you "failed" paper 1 (which I highly doubt you did), it's not impossible to get a 5. You just really need to work hard and try getting as many marks as you can