Rehearsing without Earplugs Was a Bad Idea...

Get high quality musician ear plugs. I use ACS brand custom plugs with 26db filters. They are surprisingly effective at reducing noise all across the spectrum and I'm very impressed as how well they attenuate lower frequencies. I find ear plugs with filters to be better at protecting hearing than cheap foam plugs because of the possible effects of acoustic occlusion.

Immediately get on a course of oral corticosteroids like predisolone. They can reduce the damage done to your auditory system and prevent any further hearing loss or damage. If your current doctor is unwilling to prescribe them, then find a doctor who will. Oral corticosteroids have been proven to be very effective, but they need to be taken as soon as possible to ensure they are effective - they can be effective as far as a few weeks from the auditory damage incident but are most effect taken within a 72 hour window. The side effects are minimal for anyone using them to treat auditory damage, side effects are only an issue with long term use at considerable doses. I have a course of oral corticosteroids from my GP ready incase I ever damage my hearing any further and courses of the drug have helped me greatly previously.

NAC is a supplement which can also help a bunch.

 

I mentioned predisone to my doctor but she prescribed me fluticasone furoate instead, which I'm supposed to take once a day through my nose. do you think that is sufficient?

 

I should point out that while there is no noise in my right ear, it does feel that I can't hear as much out of it after Sunday, like something's blocking the full volume reaching it. I can hear full volume out of my left ear but the noise again hasn't stopped in 5 days, just a constant high pitched tone