So sorry re: the PF. It sucks. IANAD/IANAPT (physical therapist), but based on my own experience with PF a few years ago and experiences of friends, it's usually a combination of:
1. Rest from running
2. Doing a lot of stretching/strengthening exercises
3. Potentially using orthotics like u/bilsbie suggested. Would make sure to go in an d get a custom fitted one, and it may be tough to wean off off
For #2, the exercises that seemed to help me the most were the various towel stretches, rolling with a lacrosse ball, and doing a lot of calf raises. I even briefly went to a few barre classes on a friends' recommendation, which was kind of fun (and very humbling), but probably helped because we did tons of calf raises with what I thought were tiny weights, but was super challenging.
I had chronic achilles tendonitis and ended up getting shockwave therapy from my orthopedist, who mentioned it's also frequently used for plantar fasciitis if PT does not help
For #2, the exercises that seemed to help me the most were the various towel stretches, rolling with a lacrosse ball, and doing a lot of calf raises. I even briefly went to a few barre classes on a friends' recommendation, which was kind of fun (and very humbling), but probably helped because we did tons of calf raises with what I thought were tiny weights, but was super challenging.