This is really sad. I certainly see how this stresses you out, @husbandfoodproblems , not only for the budget but also the extremely selfish behaviour and his intractability.
It looks like he definitely has an eating disorder - the food videos, extras on everything and the rage when challenged all speak to a severe addiction. Such things are not easily fixed, regrettably - they usually go right back to early childhood.
So, if you can't change him and aren't ready to leave him, the only thing we can look at is how to satisfy his bottomless appetite without breaking the budget.
I may be on the wrong track here, but sausages and bacon are quite unsatisfying per £ spent and are also quite poor nutritionally for the cost. If they sell cheapo chickens & pork joints where you are, how about getting those so there's always a LARGE amount of protein-rich, cooked meat in the fridge? As a rampant carnivore on a tight budget, I'm extremely grateful for budget pigs & chickens!
I also stock up on pork 'steaks' and mince, because they work out great value per plate of high-protein meat. Bags of frozen chicken pieces often work out very cheap, too. And eggs, most filling when fried. You can get very cheap frozen and tinned fish.
Does he cook for himself? If not, make huge pans of rice and pasta, preferably wholegrain because it's more filling (and healthier). Keep them in the fridge so he can help himself at will. If you think it'll help, put bowls of made-up pasta sauce (with meat or fish) and curry, etc, to go with it.
Fried bread may be lethal in the long run, but it's incredibly satisfying and cheap. Lovely with lots of salt & pepper. You can also fry rice, of course.
I think it's a great idea to make yoghurt if he can be persuaded to use it instead of cream. You can put sugar in the mixture and, the longer you leave it warm, the thicker it gets.
There's no point in getting coco pops if he's just going to add cocoa anyway, get plain old cereals if they're cheaper!
No clue whether any of this will be helpful, but if it even gives you ideas I'll be pleased.