Welcome Vaneza! Well, I sure am sorry to hear about your bunny, but I am happy that you were able to find a way to get him to a vet asap. It's good to get established with a rabbit savvy vet, so though this may not have been the way you wanted to do it, at least you'll now have a vet to rely on.
Also, I understand that vet visits can really be expensive. Most vets take credit cards so hopefully you won't have to only do cash. Also, you may want to see if the vet you see takes "Care Credit" It's a lower interest rate credit card for health services only. You have to choose whether you want to use if for human health or animal health (but you can also switch back and forth I believe as long as you call the company) Anyway, I also like the care credit because I can't buy new shoes, or anything else that catches my eye, and so it always is in my wallet only waiting for emergencies.
Also, I have VPI pet insurance, and they would have covered the costs about 70 - 80% ( You still have to pay upfront with most vets, but the insurance reimburses within a few weeks). It costs around $12 dollars a month, and you get a discount if you have more than one animal on it.
Things I know they don't cover include parasitic stuff, like fleas, mites, worms and e.cuniculi. But they cover infections and digestive problems. Both of which are common in rabbits and can really cost a fortune. I always say, you pay for the vet, not the pet. Vets are expensive. I just spent over $500 in the last week. Rucy had her spurs trimmed and an e.cuniculi test. And Bailey had x-rays, and treatment for e.cuniculi.
I'm sending healing vibes your bunny's way. Keep us updated.