Help Cheeto and Mini with their health

I adopted Cheeto and Mini about 3 years ago from a rescue. No background history as they were abandoned but over all healthy. fast forward to now and Mini has on going health issues and is in need of a biopsy as well as other medical needs. She is on and off different medications. And Cheeto just tore her ACL and will potentially need surgery to correct that. Both of them have a lot of vet visits and I’m out of my depth on trying to manage them financially. Any help you can give to help my babies is a blessing.