learn to be a tattoo artist

i have the drawing down whenit comes to the art part of tattooing. i actually draw tattoos for many people i know and many of them would want me to do the actually tattoo since i am the creator of the drawing . i would loive to do this but i dont believe i have the guts to do any ink slinging on a person know if i mess up it permanent… any advice on how to get over this?? cause i really want to its just that one thing stopping me…