I agree with Laura and Indigo, finding and seeing a good therapist can help you deal with you food addiction. Having an addictive personality is a hard issue to handle. You don't want to trade your food addiction for another destructive behavior and a therapist can help you. You're strong as a cancer survivor who has been through surgery and can do this.
I'm not a cancer survivor but someone who has undergone 7 surgeries in 6 years including the sleeve, and will be undergoing my second neurosurgery in a year in the coming weeks. So, I know how you feel, as someone who has survived a life threatening infection. Sure, you're afraid and freaking out as many of us are (were), but we made it or will make it through and so can you. Let the therapist help you resolve your issues with food, and not let you mind keep you from saving your life. Good luck to you, and remember we're here to support you.