Welcome to the Chronic Pain forum of Healing Well. I'm so sorry you have to be here, especially at such a young age. The first thing I'd suggest is also posting on the fibromyalgia forum, which you can switch to easily by using the quick jump menu at the top of the page. You can post to both forums, so you can be here, too.
I have had plantar fascitis, and it still returns - and as a matter of fact is back because I've been slowly putting the 20 lbs. I took off 10 years ago back on. For me, that was the one thing that got rid of it. Ten years ago I did some PT for it, learned the stretches, etc. and wasn't obese but had put on those extra lbs. slowly. Once I took them off the pain went away. Now the reverse is happening. But I know this also happens to runners and other athletes. All I can suggest is to follow your PT's recommendations, and definitely don't over do it. Oh - and the shoes you wear are very important. For a long time all I could wear was my supportive walking shoes, but I "graduated" to Birkenstocks and such, but I still can't wear any kind of hard shoe or heel. Of course, now my back is also an issue, and I'm lots older than you, but shoes can matter!