Last night, Oscar didn't eat much of his bland chicken and rice dinner and at 11:00, he had bloody/jelly diarrhea again

I'm so sad right now. He was just at the vet last week getting treated and now he has it again. I also feel bad for my parents, who are paying for most of the vet bills and it's reaching to $1500 right now. I just want my Oscar to feel better and be back to normal.