Gastric Byp, any succesful stories out there or horror stories?

I am 41 and have plaque build up in my arteries, heart dr wants me to have gastric byp due to being obese, but I am scared I won't make it through the surgery. Has anyone been succesfull with the surgery, what is the worse part? What kind of complications did you have? Need advice, I have to get this weight off, dieting hasn't been succesfull, and I scared of dying if I don't have the surgery, scared of dying if I do have the surgery. Serious answers only please.