Hi, Welcome to JustAnswer. I am a licensed veterinarian and I'm here to help you. I just came online and saw that you are waiting for an answer. . .sorry it has taken over a day to get back to you.
My main concern for Roxy is that she has a pyometra or uterine infection. Since she has the vaginal discharge, this means that she could probably be treated with antibiotics successfully and this would not be a complicated or expensive treatment.
The best place to find this veterinary care with easy payments is at your own vet with whom you have a relationship. If that is not an option, then you might find a vet that offers Care Credit. This is a service that allows most everyone to charge their vet bill and then make payments to them.
Hope this is all helpful to you. If you have any further questions or concerns, please just let me know. Thanks!