Ive heard it comes from burning the gays with the kingling that is used to burn witches, is this true?
This is not my area of expertise; however I do have a passing interest in etymology and linguistics and can point you in the direction of a fascinating and entertaining source. The answer to your question is: no.
In the amazing Slate podcast Lexicon Valley, they have an episode on the history of slurs, and they start with 'faggot.' What they uncover in the scholarship is that the likely origin comes from, indeed, faggot as a piece of kindling. However, the word was next used metonymously to refer to old women who gathered such pieces of wood. This effeminate and degrading term was then applied to people who engaged on the receiving end of homosexual behavior.