Is laser hair removal considered an urgent necessity for revealing the 'awrah, given severe pain and inability to remove it by traditional methods, especially with the wedding date approaching, and what is the ruling on the session that has already taken place?

If you are unable to remove the hair yourself and it causes severe pain, there is no sin in seeking the help of a female doctor to remove it. This is supported by the stance of the Hanbali jurists, who permit someone who cannot remove the hair of their own awrah (private parts) themselves to seek the help of another. However, necessity is assessed according to its measure, meaning it is not permissible to touch or look at anything beyond what the necessity dictates.