goodness - I feel so sorry to hear this. We launched an appeal knowing full well that our school of choice never upholds any appeals for any reason whatsoever (not disability / emotional / family reasons - nothing).
We did however feel that we had no option but to appeal as our child was academically suited to being there.
Sometimes you have to consider how you may feel if you later start to wonder what might have happened. I would bayyen down the hatches and gve it a go. Just be prepared to accept failure at the end if necessary.
Have a very good second choice of school ready just in case (we didn't) and don't ever discuss it in front of the child!
Hope that helps!