Two year old cat with severe anemia.

I have a cat named Blu, he just turned two this summer. About two months ago he had a serious medical emergency. He became very lethargic and would hide in places he normally would go and had a loss of appetite. One night I noticed he was laying in his litter box and he was still there the morning after. I immediately took him to an animal hospital thinking it was a possible UTI or something like that.

After the veterinarian looked at him she diagnosed him as severely anemic and said he would need a blood transfusion and further testing to find out why this happened which would cost almost $4000. I made the decision to just bring him home that day and keep him as comfortable as possible on a steroid and antibiotic. I had lost all hope at that point but to our surprise after a few weeks he actually started to gain weight back and seemed like he was returning to his normal self.

Now a few months after that, he's been off the meds for awhile now and eating and drinking and playing normally until about a week ago, I've noticed that he is beginning to get lethargic again and has a loss of appetite. I'm curious if anyone has had experiences with young anemic cats and is there hope for such a young cat to beat this cycle? I made a vet appointment for him tomorrow I'm hoping they can give me answers.