This leg pain issue appears to be an extremely difficult problem for you to get past. I suspect that if fasted long enough, you would come through it successfully and permanently but neither of us seem to be completely confident in that belief.
In a situation like this, the sensible option is to attend a fasting center where you can rely on the confidence of a professional fasting supervisor to see you through the tough part. Trying to do it on your own is too scary and on that basis alone is doomed to fail.
If this is not possible for one reason or another, then perhaps a telephone consultation with an Hygienic doctor would be sufficient to set the stage for long-distance fasting supervision. Either way, I believe that you need that personal attention to get through what might in the end turn out to be an easy hurdle.