Unfortunately, you are going to need to seek veterinary attention again. I have had a hedgehog who had chronic inner ear infections, these are extremely painful. If it continues for too long serious consequences can occur, the ear drum can burst, permanent damage to their balance and hearing can result, etc.
Ear infections can also be a symptom of a much worse problem. For instance there could be a tumor inside the inner ear causing infection. For mine, we later learned he had leukemia and the ear infections were likely being caused by a weakened immune system.
With the one that I mentioned above, we were treating him with an antibiotic and it wasn't working well enough to fully treat the infection. We switched drugs to try to combat it. Sadly his infection got bad enough so quickly that his ear drum burst, when then required a surgical procedure to flush the blood and pus out of his ear.
If you cannot afford the veterinary care for him right now, you may need to seek other avenues to get him treated. Ask family or friends for a loan to help pay for his care, apply for Care Credit (google it if you aren't familiar), or if the worst happens seek a rescue group to take him in (depending on your location we may be able to help you out).