I've given some thought to your issue with Brad and why he might not be joining you in an effort to be healthy. Please don't take any of this as a slight on you. Clearly you are doing your best, have great ideas, energy and action. There are so many more demands on you and your time than I have that I can't even imagine being in your five-fingers.
That being said, one thing I have noticed about people is that they are funny about complexity. If something is a fun hobby or an interesting job, they welcome complexity. The more the better sometimes if only to keep some air of mystery about what they do for outsiders. Complexity in things they don't think are fun or interesting is usually met with resistance. My reading of your journal tells me that you've made changing your diet complicated. You have many books. Rules. Gadgets. Recipes. Stress over your son's behavior. Your weight goes up and down. If I were Brad, I wouldn't invite that into my life either. It's intimidating.
I think that applies double for a diet. Dieting is alien to men unless they're athletes. Training regimens are acceptable and when I met my husband he had one. He ate a bodybuilder's diet and didn't consider it weird. Before that he was a runner and ate for that. Men don't usually diet to lose weight, they diet to train. Women pretty much approach dieting as a normal part of their lives. We practically learn calorie counting in our cradles. We automatically choose the low-cal, low-fat variety of anything while men mostly don't. We refuse dessert, second helpings and extra toppings. To restrict what they eat is foreign to men, while for us it's natural. From where I'm sitting, if I were Brad, I'd see your diet as just another one of the many he's watched you try since he's known you. It's a woman thing. Because he doesn't seem to be an athlete, it's not something he can compartmentalize in his world or apply to himself.
Another issue is that a fat man still has value while a fat woman has none. In his life nothing bad happens to him because he's 300+ pounds. There are plenty of fat men on TV and elsewhere in public life. Yes, body issues exist for men, too, but not nearly so much as for women who are first and foremost valued for their looks. Men can be fat, balding, have bad teeth, gray hair and wrinkles and will still be a tv presenter. A woman has no such leeway. So I think he feels safe as he is. Accepted. Valued. Being that he's relatively young, major health issues aren't a problem, but you've listed some minor ones which unfortunately can be "solved" by taking a pill. At least in his eyes.
So what to do?
I know it's going to sound like I'm being patronizing or that I don't understand the whirling vortex that is your life, but I'll say it anyway.
Stress about the stuff that really needs to be stressed over - money, job, kids, bills.
Let the rest of it go. The meals, the food, the housework, the scale. Take the complexity and stress out of changing the way you eat and as many other things as you can. So people leave socks on the floor, so what? It's not like the roof is falling in.
Maybe try to find something athletic you can do together. Something he will have to work to accomplish and shift his eating to further his athletic performance. That one might be a stretch. My hubby is a natural athlete and has always connected the dots between performance and food. Regardless of what Brad believes though, the dots do connect and maybe putting that into an athletic context will help him out. Of course body-builders/power lifters/sprinters need to eat a certain way, it's obvious. At least to men with athletic leanings.
Anyway...I'm rambling now, but that's my take. I know you're worried about his health, but he isn't and until he is I doubt he'll do anything to change. It may take something major, but maybe if he sees that this diet isn't really a "diet" and that it isn't complicated and stressful, he'll think about it differently. Maybe if he has an athletic goal he'd like to reach, he'll approach what he eats differently. Either way, he has to come to it willingly and enthusiastically, otherwise it's just drudgery, and who wants that?
Sorry that was so long. Hopefully it helps. Keep on keeping on. You're a determined person and I'm sure that you'll find success for yourself.