Steroid injections can help but often only mask the problem especially since most people as soon as they feel they are pain free return to their normal activities thus abusing their foot and not letting the inflammation subside. It is a very difficult condition to treat since one has to walk on that foot, but there are things you can do to help.
The more you stick to the advice given to you by your doctor the less likely the condition would develop into a chronic one. If you are hypermobile you have to pay extra attention to it.
You have to stretch your foot at least 4 times a day, you should have been given the exercises by your doctor. If you have ever experienced muscle ache following a previous day�s rigorous exercise then you would know that a gentle stretching can either prevent it or elevate it. The same applies to plantar fascia. If you have a partner, have them massage the painful area with the thumb/knuckles applying moderate force rubbing the area without losing skin contact. After that you can apply Ibuprofen Gel Max (get the 10% one rather than 5), it�s an anti-inflammatory so should be of great benefit.
Make sure you have well supported foot wear, nothing thin soled and try to avoid walking barefoot.
And last but not least, remember once the pain starts going it does not mean the area is healed so allow for another couple of months to let yourself to get back to normal.
Good luck and speedy recovery.
S.