Please help Harley with his tumor & infection

Hi. My name is Bonnie and this is my kitty, Harley. He has had a rough life, being abandoned outside for a few years. Once I got him, of course he was fed and loved, then got his shots and neutered. He has done well learning to be inside and has such a loud purr! However, he now has a big abscessed poking out of his mouth and infection all through his mouth. The vets office told me it would cost about $1000-$1500 to get it all taken care of. I really don't want him to have to deal with this, so I really need some help for him. I hate asking for donations, but Harley is worth it. He is such a good boy. Thank you for reading this and if you can donate, I appreciate you!

BTW, that is the tumor in the picture, not his tongue.