Diagnosis? There are many foot injuries? How do you know that you have plantar fasciitis?
There are several threads on PF in the last 2 years of this forum with lots of discussion and links. Heelspur is a good website to start and has lots of information. See pain location on Heelspur. They do promote some products.
Tissue Injured? It has never been clear to me which type of tissue is most injured, tendon, muscle, ligament, fascia, other. ? Tendons newly injured take at least months to heal and longer to remodel. Just when you can use tendons after an injury is not clear from what I can find. My personal decision is it's a good idea to take at least 3 months off. From what I've found a few weeks is not enough time, where does that come from?
I had plantar fasciitis in both feet. I played on it and it got slowly worse over almost a year. I finally took off for 3 months. When I started playing again there was still a very light pain so maybe 3 months time off was not enough for that particular injury of mine. It improved and has not bothered me again. I have a friend who had it also for a long time and took off for a year. He was OK on returning.
Tight Calf Muscles.? The injury might be associated with short/tight calf muscles. Tight calves can be related to life style issues such as sitting with the feet pointed - calves shortened - for too many hours of the week. I would not exercise or stretch an injury without being reasonably certain that it was not doing added harm, getting a Dr's approval, etc..
Night Splints, to hold the ankle at a right angle, can reduce the sharp morning pains. Just saw a night splint at ...mart that look well-designed and was low cost. However, a similar splint that fitted on the top of my foot with a strap under my toe joints causes me some new pain at the toe joints not related to my PF.
NCBI PMC - free full research publications on medical and biomechanical subjects
http://www.ncbi.nlm.nih.gov/pmc/?term=plantar+fasciitis
http://www.ncbi.nlm.nih.gov/pmc/?term=plantar+fasciitis&report=imagesdocsum