UPDATE: My boy is sick. Advice?

Soooo...for any of you that read my previous thread and wanted an update, here goes:

We ended up taking him to the vet a day early and they recommended we go to the emergency clinic for an ultrasound.

Paid for an overnight stay, blood work, ultrasound, pathology panel, etc. $2k later we got "an abscess on a lymph node on his right abdomen...not lymphoma, but could be an infection with fluid or a blood clot. We'd like to do exploratory surgery so we know what it is for sure so we gave him no antibiotics. It'll be $8k for the surgery"

I pulled his ass out of there and went straight to my buddy's vet that more or less set up his clinic purely in response to people being gouged at this hospital. Every animal he's had to take there over the years conveniently costs $10k and they still give shit prognoses.

New vet is fantastic, really truly cares about the animals and their owners. Charged us for 1 exam so far and only drugs since. We've got him on 2 antibiotics and a pain med and I've taken him there at least every 2-3 days since. His fever is gone, he's eating again, his blood test came back all normal and he's much better so far. Only issue now is he hasn't pooped in a couple days and we have some laxatives to move things along.

We're scheduling a followup ultrasound after the course of antibiotics is done to verify the abscess is gone but it's already a big change back toward normal. Bonus is it's still less than half the cost of the emergency clinic. Fingers crossed we're beyond the worst of it.