You have my deepest sympathy on that mate , I lost 1 1/2 years of running to PF from middle of 2014 and virtually all of 2015. Nursed myself back into running during 2016 , did a 5km parkrun PB in October that year and my first marathon for 20 years six months afterwards. So the message is you can definitely recover and get back to running again.Just getting back to my running after nearly 2 yrs of due to suffering from plantar fasciitis anyone who's suffered from it will understand the pain it causes, up to 3 miles not sure I'll be able to up my mileage still have a little pain so properly at my limit.
I researched everything on PF while injured , I could do a PhD thesis on it , and I’m sure you’ve done similar, somuch conflicting advice and everybody is different . While I don’t currently “suffer” from PF I do consider I’ve still got it , in the same way a recovering alcoholic/ gambler is aware they can’t let things slip. My PF originated from my calves after doing increased mileage and adding in hill sessions. I now use a hand held foam roller on my calves 4 or 5 times a week, just a few minutes on each one is enough for me.
I won’t bore you with everything I tried, but acupuncture helped to break it and I really don’t want to go back to having Dr Wu sticking needles in the soles of my feet again! Good luck with your recovery.