I personally just had to give up on a goal on running a half marathon in December.

It is about a month out... and I have had this reoccuring leg pain... not the same as yours... and it's not muscle pain... I bought new shoes which helped for about a week, then the pain was back.

So, this past weekend, I had to come to the realization that there is no way I can make it 13 miles running. I have been training so hard... but I know it's my form... so I am going to sign up for a running class next year... and hopefully I will get my form in order... so I can run further than a 5K in the future.

Sorry I couldn't be of more help... but my experience is similar to yours... so I feel your pain... literally!