Plantar fasciitis is common and like any other problem that is common there is so much snake oil that gets marketed for it and bad advice that gets given for it. Because of this, so many cases get mismanaged and what should be an easily managed condition become a chronic difficult to manage problem.
The classic symptoms of plantar fasciitis is pain under the heal that is generally worse when getting up from rest. If you have those symptoms, then there is a pretty good chance that this is what it is. However, there are a few uncommon problems that can produce the same symptoms, hence the need to getting the diagnosis right. There is nothing wrong with self-diagnosis or self management as the simple cases are easy to treat. However, you do need to be aware that not getting one of the more uncommon conditions diagnosed and treated early can lead to a lot of unnecessary pain and discomfort.
Plantar fasciitis is due to too much cumulative load in the plantar fascia beyond what the tissue can take. This means that the basic treatment has to be directed at reducing the load and increasing the ability of the tissue to take the load. Any other treatments are just directed at the symptoms and not at these basics make a lower probability of success over the long term. There is so much differing advice been given of differing quality that may or may not be based on the most recent available evidence.
Whatever is going on with your plantar fasciitis, get the right diagnosis first and get the treatment that the scientific evidence has been shown to work better than a placebo, rather than rely on anecdotes and poor quality non-evidence based interventions.