Four days ago, my 3-year-old cat Bella started acting strangely—eating less, losing energy, and now she’s barely eating or drinking and can’t even make it to her litter box. I took her to the vet yesterday, but they couldn’t figure out what was wrong and suggested blood and urine tests, which are too expensive for us right now. The vet ruled out poisoning or a virus, noting that her gums, ears, and eyes are very pale, possibly indicating anemia. I’m really worried and don’t know what to do. Does anyone have advice on what might be wrong or how I can help her at home? I’m searching for a more affordable vet in LA County, but if I can’t find one, I’ll go ahead with the blood test at our appointment today. Any recommendations for affordable vets in the area would also be appreciated.
Not trying to be mean, but perhaps you should consider surrendering her so she can receive the medical care she needs.
The only way to know is to do the labwork and probably some imaging like X-rays or ultrasound. Have you looked at applying for CareCredit?
You must either apply for CareCredit or find a cheaper veterinarian because there is no efficient method to help her unless she undergoes tests and the root of her disease is identified. Bloodwork and radiography are both expensive, yet it appears that your girl requires these procedures.
Hey, low-income vet? @Rosie_Tailor
If Op is in the USA, county vets are cheaper.
If the vet who saw her in person couldn’t diagnose her without more tests, it’s unlikely the internet will be able to either. 
If your cat is unwell, it’s best to take her to a veterinarian for a professional diagnosis and treatment.