My goldfishy

Please help! my 4 inch goldfish has a 1cm diameter hole through a part of its back. I woke up this morning and saw it stuck inside a peice of drift wood and i was shocked to see through the goldfishs wound. you can see all the bones flesh and light from the other side. please anyone have advice. it is already seperated and please do not ask for pictures since Louis is very busy these days.