so upset

My son got circumcised the day after he was born and everything looked great. I was told to put Vaseline on it for the next couple days which I did. A couple weeks later I noticed there was extra skin that was able to come up over the tip of his penis. So it looks like he's half circumcised half not. I was just told by the dr he will have to get the surgery done again. I'm so upset right now. I don't understand why this happened. Has this happened to anyone's son and have they had to get their circumcision done twice ?