Ooh! I feel ya! I've had crippling plantar fasciitis before. In both feet. My tips 'n' tricks:
1) be kind to yourself. If your feet hurt take a break and don't beat yourself up (this was a hard one for me)
2) you can never stretch your calves too much.
3) first thing before you get out of bed: stretch your calves, massage the bottoms of your feet
4) freeze a water bottle and roll it under your arches when your feet are sore
5) if your feet are up for it, use your bare toes to scrunch up a towel. Feels like toe push ups
6) swim! Aqua aerobics! Bike! Do all kinds of non-weightbearing exercise because losing a bit of weight will ease the load on your feet too
7) if your budget allows find an awesome physiotherapist.
8) GOOD LUCK!!!!