Lets see how this story doesn't make sense.
1. i had a cut open blister on my foot.
2. It was all white.
3. I got out of the creek, I looked at the blister and it was black [How was it white and now black?]
4. I ripped open the blister which kind of hurt and rocks fell out of the blister. [You just said you did and now rocks fell out of it. [If they did how did the first time you opened the blister rocks never fell out of it?]
It takes a few minutes to see how this story is not real or doesn't make sense.