Greetings & salutations! I’m a true-blue PFS recoveree and occasionally post “recovery cheerleading” threads to perhaps inspire others to hang on!
See my prior posts but my short simplified story is (1) I took FIN for 15(!) years which in 2014 (2) triggered profound sleep dysfunction which continues (3) and separately triggered worst-case scenario PFS which resolved naturally in 2.5 years (4) by incredible dumb luck I survived several serious suicide attempts and (5) in 2020 sued Merck (too late so had to dismiss.)
Unfortunately my PFS recovery is a mystery and I can’t recommend any solution other than enduring PFS until you perhaps naturally recover!
(1) I’m happy to report my insane sleep dysfunction is now partially controlled by late night exercise, reading & Belsomra (which I’m not allowed to discuss in detail). I now sometimes get 3-4 hrs sleep plus endless “zombie naps” (partially conscious rest).
(2) Steer clear of alternative medicine purveyors. I tried “pill therapy” in 2016 and it was voodoo gibberish despite being administered by former MD! Someone recently offered “mindset therapy” to cure my lingering issues but I smartly steered clear! They promise their dubious remedies can cure anything 
Good luck!