First of all, you got to check it out with the doctor, and if it is not some genital desease like others suggested, there is an excellent cream to use, and may take the itchiness or even cuts inflamation etc away pretty quick!
The cream is called Ungvita, it is a vitamin A cream and it heals burns cuts without leaving scarring behind, and assists with itching. Most times, it helps relieve the problem the same day as much as 80% effective. The only draw back is its fishy smell, but you can counteract that if you spray some cologn in the nearby areas.
The company makes another for babies rashes, and that smells nice, but it is not much effective as it does not have as much vitamin A as the fishy one (though if the smell affects you that much (I doubt it) you can try the other one for rashes).