WTF - foot pain, is my OC 100k in jeopardy??

My last post talked of me doing the Youngstown (ohio) Ultra 50k - welp, didn't happen.  I thought I had been pushing myself just right.  After the Drakewell marathon on August 18th, 2013 I kept hammering away at the miles and apparently it caught up with me.  A few weeks ago, the bottom of my left foot (ball of foot) began aching pretty good and was only getting worse.  Here is a synopsis of my training during my painful time with corresponding notes that I put down in Dailymile.com:

• 9/3 - ran 7.5 miles (left bottom foot started aching, cramp?)
• 9/4 - ran 3 miles, no issues with foot
• 9/6 - 10.1 - .left foot crampyness hit about mile 7....didn't prohibit running just noting it in case...
• 9/8 - 10.18- but pain under left foot (under middle toe area) around mile 7 - 10.
• 9/10 - 7.5 miles - wow, my foot was aching pretty good yesterday - however it would come and go...started around mile 4...then go away around mile 6...I don't get it...its not constant. Bottom of the left foot, under the toes (pad area). I am thinking prob shouldn't have run yesterday. I will take the next three days off and see if I can do this 50k on Sat...this is not the time for an injury.
• Did not run from 9/11 - 9/18 and took off Youngstown ultra 50k...
• Did not run the youngstown ultra 50k
• ran 5 miles on 9/18 - no real pain...some twinges - ran with the Hokas
• Ran 5 miles on 9/19 in road running shoes (brooks ghost 5)
• Saw Chiro on 9/18, could be stress fracture or metatargligia
• Saw podiatrist on 9/20/2013, informed me that it was not a stress fracture and that foot bones looked healthy.  Did other test by examining the 2nd metatarsal where the pain seem to be.
• Said it was a neuroma under my 2nd and 3rd metatarsal.  After some debating, I got a cortisone shot.  Note:  I NEVER take anti-inflammatory medicince ever but given the pain and that I had 16 days till OC 100, I took a chance and the pain is gone.  Now, I know this is a temporary solution and plan to take off significant time after the 100k.

As of 9/21/2013, things are looking better.  Hit the bike for 12.1 miles and did 3 sets of 5 minute uphill climbs.   Will be doing an hour on the bike tomorrow and then start back running next week - probably get around 25/30 miles in (if I can).

I will keep an eye on the foot though but it is feeling better.