Help my dog, please.

My dog's name is Rick Freddo, and I've had him for a year now. When he was around six months old, I noticed that he was getting patches of missing hair and some rashes on his belly. The veterinarian gave me a prescription for food allergies. His skin turned very dark and the rash worsened. Seeing my puppy like that was very sad. He couldn't get exposed to the sun or play with other dogs. Finally, after many months of visiting different vets and trying new medications, they told me that it was probably scabies. His skin started clearing out, and he felt better. About a week ago, I noticed another rash on his body. The vet tells me that he has to have more tests done and start treatment again. The medications and the visits to the vet are super expensive. My parents pay for my school, and I pay for my dog's expenses. Because of COVID-19, I lost my job so I can't afford it. I am very grateful because my family is helping me with what they can. Freddo is so sweet and loyal. I love him so much.