So I’m am a 21 year old male I am not gay at all I have a gf I love girls would never think about doing anything with another guy

I need some help and some thoughts about becoming a shemale or going all the way to a transgender and also how to tell my girl friend I don’t want to lose her at all and she is a really cool girl and doesn’t judge me at all but I fell like she might this time

So please let me know of the ups and downs and thoughts thanks