I developed catastrophic hyperacusis and tinnitus more than 11 years back. We're talking closed storm windows in the summer without air conditioning because the sound of crickets and other people's air conditioners sounded like Boeing 747s. I'm happy to say that the hyperacusis has pretty much fully resolved. I'm just slightly more sensitive to sound than I perhaps was, but I believe that is mostly due to tinnitus which fluctuates between moderate and severe, and has even approached mild.
I don't know if this is what reduced the hyperacusis, but I'll share my approach. I took walks in the woods, tried to surround myself with nature, saw an acupuncturist twice a week (he is the only one out of about 7 acupuncturists I have visited able to reduce the hyperacusis and tinnitus), took Ayurvedic herbs and massaged myself with Ayurvedic oils meant to calm the nervous system. I did alternate nostril breathing and Bhramari breathing as well (pretty much standard Pranayama done in many yoga classes). I also played lots and lots of very mellow acoustic nylon stringed guitar. I did this for hours on end, sometimes the same song repeated 5 times over. For some reason, that was soothing while a CD could drive me to distraction as I also heard the inner electronic workings of the CD-player.
For whatever reason, things are way way better now. I'd say the hyperacusis began lessening within months and was just about gone within a year.
So, I'd also say, hang in there! Bottom line for me was reducing anxiety which was off the charts, getting a decent night's sleep (which was impossible for the first 3 months or so), and centering my mind elsewhere whether music or nature.