I also got gyno (this is why I went off Fin to begin with).
And just like you I got testicle ache, but only in my left nut. This was about 6 months into treatment and I didn’t know it was due to Fin.
After I quit my gyno went away in maybe 2-3 months. My left nut probably took closer to one year before it went back to about normal
Many symtoms stuck with me longer or are still there, but these issues (mostly) resolved with time.
Although my balls didn’t hang as low as before Fin. I then recently started with Creatine which is a known upregulator of 5AR.
This has fixed my balls so they now “hang”. It didn’t do much to help with sensitivity or libido (yet atleast). So it’s in no way a “cure” but atleast it relieved some symtoms.