I won't be able to help much - especially as post treatment CK. I agree with Vivian - at least talk to the CK team and see if they recommend a follow-up MRI, steroids etc to potentially reverse some of the loss. I am not sure if steroids help with word recognition scores or not.
It sounds from your post that while you have lost some hearing ability (i.e. the beeps - or pure tone average) the real issue is the loss in word recognition.
I can only relate situations to my position as I am very new to this AN scene and have no medical training - just an immense curiousity.
As background (this isn't about me - I promise), I had a hearing test today and absorbing the results - but it is somewhat similar to your situation (but much more mild). While my PTA average has barely changed (25db on the AN side) the word recognition score (at 50db if anyone is as curious about this stuff as me), I only recognize about 76% of the words. This is much much much lower (statistically significant) than it was 2 months ago.
As the audiologist and ENT explained, loss of word recognition is very common with ANs. In my case, it is the result of two issues - one the AN is damaging the hearing nerve (which equates to both hearing loss as well as lower word recognition scores), the damage is permanent and irreversible and will continue and second the other side is taking over (the use it or lose philosophy).
The hearing aid which it seems you got for the AN ear can only amplify sound - it cannot make a fuzzy word sound clearer. So, regardless how well tuned your hearing aid may be - you will hear the noise of the word, but may not have a darn clue what is being said. In my situation, it may as well be the television is on in a foreign language - I can hear the noise, I just can't distinguish the words all the time. The louder you tune the hearing aid - the more noise you will hear, but won't help to discern the actually word.
Thus, at 20% word discrimination, it may make sense (according to your audiologist) to switch the hearing aid to your other ear. I will gander you must have a hearing loss on the right side as well.
Your situation is different than mine - the audiologist suggest I am very early borderline, wouldn't recommend it, but still an available decision to get a hearing aid - not because amplifying sound will help with my word recognition, but will help to keep the left ear busy and potentially slow the decline in both hearing and word discrimination (back to use it or lose it). For the record, I will wait for the next hearing test (6 months) to see if this was a true result or if the scores continue to decline - then re-evaluate.
So, one very long description that may not be worth much. I am sorry you are struggling so much with your hearing. I would push to get back to the CK clinic to hear their perspective - as they may have a few suggestions. I may also contemplate a different audiologist as this decline, according to the audiologist team at my hospital and my ENT, is very common with ANs - you may need a different type of support to help with the various options.
Good luck and again, sorry for the long message.
Ann