Why is there a difference of opinion on sex changes for transsexuals?

Hi I am 27 years old man and I recently found out that the unstoppable urge that I felt since I was a kid is called [Transsexuality](https://en.wikipedia.org/wiki/Transsexual) . Now my question is, why is sex change forbidden for Sunni Muslims while it is allowed in Shi'a Islam? Also there is no specific mention of transsexuality in Quran but by simple logic of "there is cure for every disease" can sex change be justified? It would be great if they get answers from experts. References are appreciated.