Plantar Fasciitis Stinks!

So you may recall that about three weeks ago I came down with a case of plantar fasciitis in my left foot.Well, it really stinks. I've gotten it to the point that I can barely feel the pain during the day, however I tried to run on Friday and I only made it 2.5 miles before I had to hobble my way through the next .5 mile to get 3 miles in. For the rest of the day and the next morning I suffered a bit and could be seen hobbling around. Today, three days later, I'm barely feeling any pain again. Do I try to run on it again, this time outside and not on a treadmill (I was trying to avoid the 90 degree heat and humidity...)? Do I wait longer? I have missed two weeks of my training plan already and don't want to get too far behind! What should I do?