Plantar Fasciitis (PF) is typically a symptom of very tight calf muscles. Have you recently started running? Changed your running form (which can ask more of your calf muscles)? Taking on too much running too soon? Weak gluts muscles resulting in the calf muscles taking up the impact of running? Compensating for another nagging issue or injury? Little to no support in your cycling or running shoes?
There are a host of reasons why your calf muscles can tighten up and remain tight. When they do, they start pulling on the plantar fascia (and sometimes on the Achilles). Thus the first thing you must do is get in with a good sports minded physical therapy practice to have them:
1) release your deep calf muscles (typically with dry needling)
2) address/resolve the underlying issue
You have to address both of these concerns or the PF will return as soon as you start running again.
If you are looking for a good sports minded PT practice that accepts most insurances and has a very good history of resolving endurance sports-related injuries, as a triathlon/running coach, I send all of my athletes to Advanced Kinetics. They treat with a concept needed for endurance athletes and not found with most PT practices (which is fine for 99% of the population, of which endurance athletes are not).
Good luck with your rehab! The best thing you can do is get on this early before it gets worse…just like you are doing.