I was diagnosed with FD back in 2013. It took me a very long time to get out of the thick of it, but it can be done. Remember every case is different. Mine was comparatively mild and mostly affected my index finger. I had a great teacher. His name is Jerald Harscher, and you can find his website at http://www.thepoisedguitarist.com he cured himself of focal dystonia and offers lessons to those who want to do the same.
I had to study body mapping and using my hand/arm more efficiently. In the end, Jerald turned me onto a recent concept that FD falls under a broader umbrella of what doctors are referring to as Mind Body Syndrome, or MBS. The idea is that people store the stress of unresolved traumatic life events and it manifests in physical symptoms. There is a great book on this topic called Unlearn Your Pain by Howard Schubiner MD and I highly suggest picking it up.
I don’t know if I’m 100% “better” since 3 nps legato still feels very tense, but I’m playing how I want to play, and that’s good enough for me. I do a lot of 2nps licks and Greg Howe/Michael Romeo style tapping, and I’m developing my picking style more, thanks to Troy’s work. If anything, it got me to appreciate aspects of playing I think I took for granted, like bending, vibrato, phrasing, etc.and ironically, I believe I’m a better player now than I’ve ever been.
Every case is different in how symptoms manifest, but just know that you can get through it.