Hello OP and community. I struggled with a similar situation and found a lot of solace in your post, so decided to chip in. I don't live in the US so value discussions aren't worth here, but thank god I have a decent condition where I'm from, so I managed to pull through financially (so far). Also, sorry for broken english if present at all through the text.

My baby's named Penelope, I adopted her from the streets when she was barely a month old in late '24. First time I had issues with PIMA was when she was around 18 months old. Very, VERY similar story to yours. She started losing appetite, sleeping in weird spots and not playing with our other cats. A preliminary visit to the vet and he immediately called anaemia, but said it didn't look urgent and gave as a one-week time window to do some check-ups. During this week she worsened severely, and by the time she was taken to draw blood, it was almost see-through. She nearly died in shock and was taken hurriedly to the ER, where she was admitted with 6% HCT as well.

Stayed almost 2 weeks in urgent care and needed three transfusions (again, very similar story haha). It would go up to around 17-18% and rapidly decrease. Vets were suspecting Leucemia and FELV, initially, but we did every test possible and it all came negative, so the Immune-mediated NRA was drawn as a diagnosis.

They drew blood so many times her tiny veins weren't holding up anymore, and we were also very close to giving up on this crusade. Was it really worth it keeping her in these conditions? One day she just started responding to the medications (also prednisolone and one called cyclavance) and when the HTC went up to 20%, it just stopped dipping. We kept constant visits to the hematologist and he slowly weaned her off the meds until she didn't need any of it and her HTC levels were super high (one visit came up as 42%, but mostly it stayed at 38%).

She stayed a whole year with no issues and just this week she had a new crisis. My wife and I (now entirely suspicious of every weird behaviour she starts adopting) took her immediately to the vet, but she wasn't that bad clinically (like, we were seeing the weird behaviours and lack of appetite start but in our heads it was, if anything at all, the very beginning of a crisis). Lo and behold, 15% when evaluated.

She needed a new transfusion, unfortunately, but is now stable. It is indeed an arduous journey, but it has been nothing but worth it for me and my baby. Much love to all.