Theres no such thing as porn addiction.
https://www.psychologytoday.com/intl/blog/women-who-stray/201808/science-stopped-believing-in-porn-addiction-you-should-too
Did you grow up in a religious environment with sex/porn being seen as sinful? Or something similar. Could talk to a therapist about you feeling shame about sexual desire/interest.
Or is it just porn of fat women/feedism specifically? Is it because society stigmatizes fatness, or unfairly derides fat as disgusting?
There's nothing wrong with having kinks/fetishes. Just make sure you treat your partner like a real person. Outside of the porn industry in general being exploitative, the women making fat/feedee porn are fully consenting to it and making money off of it. No more exploitative than how we all have to work to survive.
A lot of the reasons fat people have health issues is because of a good chunk of fatphobic doctors refusing to treat fat patients. Also sedentaryness (there's plenty of ways for fat people to exercise and stay healthy, sumo wrestlers generally only have problems when they stop working out).
And there's plenty of sexual and non-sexual activities that involve health risks that people find acceptable. Skiing, football, MMA. Why are we as society suddenly concerned and think it's exploitive to enjoy when it comes to be overweight? Can't possibly be because people don't like it like they do anorexic bodies. It's just like BDSM. If all adults are consenting, it's perfectly fine.