One of my maxims is that you can't cancel out shit with fish oil. It doesn't work. Excess PUFAs of all kinds, yes even O3, cause oxidation and other forms of stress. Plus, do you think the hormones and other possible contaminants in conventional meat are good for leaky gut? If you have to eat less meat to buy good meat, than do it. Fasting might also not be a great choose— sounds like your body is awash in stress hormones anyway and that just increases cortisol.
Your goal is NOT to lose weight, but to heal. Try eating regular consistent meals, dialing up the calories to keep those stress hormones low. Stop consuming rancid fish oil and start eating some wild fish, a few ounces a day. Stop eating conventional meat and start buying meat from grass-finished ruminants and supplementing it with yams. Invest in a good refrigerated commercial probiotic. Try going without dairy for awhile until you are not getting these issues.
In cases like this I would actually avoid fermented foods and spicy stuff. They can be helpful, but they are like machine guns. A commercial probiotic is more predictable.
I've had issues like this before and I've been able to resolve them by bumping up the quality and quantity of food.
Also, like others mentioned, a bland diet might help. If I get into a stomach irritation cycle (thankfullly not lately), I often end up eating a diet of mostly bone broths made in my crock pot with egg yolks.