Help putts surgery tail corrrection

Hi my name is Kimberly. I have put this up in order to help me get putts surgery. He is my rescue baby from our local animal shelter. When I first got him he was 44 pounds no hair from mid back down and bullet wounds. He’s doing great accept he has really bad allergies and is on a percription called Apquill that helps with his allergies. But his last visit he has a server skin infection from who ever done a home crop job on his tail. It’s causing a yeast infection in his ears so bad he has tubes put in ever 10 days. The skin infection will not clear up until we can fix his tail. The issue is it sits right in front of his butt, so every time he goes to the bathroom it just squashes in between the folds. I clean it and do what my vet says but it’s always raw around his butt and then the poop causing the infection. He’s like my child, I couldn’t have kids. And due to my issues I’m on a fixed income. He’s my world and I feel so bad I can’t afford it. So this is in hopes that I can get some help. Thank you for taking the time to read our story. He is a happy boy just needs a surgery!!!