Oh my gosh, I had this too. I only had it in one heel and I had it from June until Christmas. Two things that I felt impacted it, constant stretching of the calf, ankle area. I did that all the time. And then I had a massage therapist suggest this . . . he said to break up the fascia. To do that, I would take my heel and press it against the edge of a step in my house. Oh, it did hurt but not terribly and was one of those things where it hurt so good, you know? I did ice, ibuprofen, rest and I tried inserts. Inserts made it worse in my opinion. But that stretching was probably the biggest thing for me. Mine would be worse at different times in the day but there were times even when not walking on it that it would just throb. I wear good shoes at all times and pitch things like tennis shoes when I think they are anywhere near the end of their life.
I hope it gets better!! and soon!
Bursa pain where? Your hips? Is the achilles problem and, if it's the bursa sacs at the hips, in the same leg as the plantar fasciitis? Which came first? I ask because it could be your mechanics of movement are way off either due to one of these injuries or it's just off. I feel for you -- I had a lot of things go wrong all at once, a knee, lower back, and neck and arms, and ended up with a ton of PT. Then I hurt the plantar fascia on, of all things, an elliptical machine, but these things usually are building before you notice them. With this injury, some get better quickly, and others don't, and nobody really knows why. If all else fails, you can get surgery for it, as a last resort. But I'm guessing, again, that you have a mobility problem that's the root of all this and why you keep hurting things along a line of movement.