I have had similar problem, though not so it kept me off the bike more than a day, and it only shows up after about 50 miles. I suggest you use either A&D cream or a "chamois butter" before heading out. Also, every 45 min to 1 hr, stop and re-butter. Forget the modesty, you probably won't know the people you are passing anyway.

Bag balm is good too, but I think A&D is better. Real bag balm is at the feed store, and was used to help moisturize and heal the udders (bag) of the old milk cow.