Wife thinks I'm losing it...

Don't make yourself a nervous wreck. Someday, I feel like I'm like that. Remember to take it all in stride. There are some things we can control and others we can't. Those you can't, simply prepare for what could happen, keep eyes open, and let it go. And even though you are worried about the corn (so am I), we don't always know which products have the GMO corn. For peace in your family, I'd do a compromise and simply limit consumption. That's what has happened in my household. Seems to work.

"Unfortunatley no one can be told what the matrix is, you have to see it for yourself."
My wife was the same way. she voted and campaigned for Obama in 08 right before I met her. We disagreed on most of the gotcha political issues and she suspected I was paranoid. She has come to agree with me on just about everything. I think at this point she knows I'm telling the truth, but part of her still doesn't want to believe that she had ever not known it all. Its gotta be tough to accept somebody who wants to tear down everything you thought the world was...
My method was to not directly oppose her or force feed the red pill, because that would only solidify her opposition more. she was not ready to accept truth so i had to present it slowly, piecemeal. Gently and indirectly inject the idea. Socratic questioning is effective too, but think it through beforehand.

For food issues, I just totally took on the role of cook. She went from eating out and microwaving boxed food to eating home cooked meals out of the garden. I took it as my responsibility to to make my fresh food taste better than the stuff with msg and aspartame. Herbs, spices, the 'fond' from seared meat can have onions sauteed on it and then deglazed with any liquid for an awesome pan sauce. and it cleans your pan.

Stop worrying. Maybe take a break from politics and then when you come back, catch up, but keep quiet about politics for awhile when you are at home. That's what I did when my husband complained about my involvement a couple of years ago. He was pretty much apolitical up till then, although he did always like Ron Paul.

This year for the first time he went to the caucus and conventions with me. He got caught up when he found out how much power one had when one becomes a delegate. He then became a delegate, as well. All that time I was not pushy. I let him take the lead on his participation level.

At home I kept what I read and believed to myself. But never once did I hide my passion about liberty at those conventions. He was taken by surprise when he saw this new side of me and he liked what he saw. I spoke before large assemblies. I knew Roberts Rules. I knew which way to vote on planks and rules. He met all the nice people I had met over the past few years. He never has complained once this past year.

You can fix this. I did. Good luck.

They must not understand what your going through

You have to stay strong, find a alternative fun solution better than their dependence But all is well in moderation of course

Making them them aware of it is important, but you can't be forcing, coercing, nagging, or generally become a sour puss. I personally wouldn't take away Halloween, Thanksgiving, Christmans, and etc.

Don't force the wife and kids, or else you will only guarantee that they will never get to where you are. Lead by example, find positive opportunities to explain why you are doing what you are doing for yourself. Control over others is an illusion, but the illusion often temps us to make it reality by using force. But that "reality" is also an illusion, since any compliance on their part is only an illusion to fool you into stopping said force. Rinse, repeat. Same situation here, wife is always on my case about eating fried eggs over easy, a true believer in conventional wisdom.

My husband and I have been teaching my daughter, 15yrs old now, since she was 9 about the dangers of GMO's, Hormones, pesticides, etc. We eat mainly organic and always GMO-free. She has never had a problem going trick or treating with her friends and then giving them the candy to take home. We always took her to Whole Foods the day before to buy some candy to eat also. I have never told her she can't eat the candy she got on Halloween, it was always her own decision and there were times she would eat a snickers or something and that was enough for her. The coolest thing is that my daughter thinks it is so gross that people eat fast food. She hasn't had fast food since she was about 5yrs old and doesn't even remember it. She says the smell of those places makes her gag and can't imagine it tastes any better than it smells :)
I hope your wife comes around. We need all the clean (gmo-free) children we can get to keep our race alive in the future. With the studies, it shows that 3rd and 4th generations can become sterile. That would not be good for the future of the human race.
Maybe have her check out the documentary "Future of Food" it is a very good film for educating on the effects of GMO's in our food supply.