Good for you.
That takes amazing willpower. Unfortunately, it can wear ya down after awhile. It just doesn't seem fair for you. What about all of you deciding to go out to eat somewhere so that you might have some options? I think that would be the considerate thing to do. Or else make them pay for an entire pizza just for you so that you can eat the toppings and throw away the crust. The scenario you describe sounds like some of my recent nightmares.
Personally, my home is my domain. Since I do the shopping, junk food doesn't come in. I will prepare healthy meals (and serve side dishes of off-limit carbs for my company). But junk doesn't come in. Most of the time they don't even realize that they are eating low carb because the food I serve is so decadent. I buy nuts for snack foods or make veggies and dip. Home is the only place I have control over food.
My DH's sister died at 50 from a massive heart attack and his family is rampant with diabetes. Ironically, DH and his 2 sisters are doctors, who have been continually misled by the pharmaceuticals. I finally laid out my position. If he wants to kill himself with junk food, by all means go ahead. However, I won't be part of it. Being such a "guilt-ridden" person, I'd be kicking myself with guilt if he died from a diet-related disease and I had been feeding it to him. I guess that's tough love, but I gotta do what I gotta do.
The sad part about low-carbing is that most of society assumes that it is just a weight loss plan, not a way to maintain health, so it often gets discounted as a WOL. I don't need to lose weight, but I eat this way to avoid serious health problems. So this is what I harp onto my family about, keeping healthy. It wasn't so unnatural to serve low-fat items to company because it was considered "healthy". So I serve "low carb" to company because we KNOW it is healthier.
Since I don't have an abundance of willpower at times, if my company insists on junk, then I ask them to store it where I can't see it and to also not offer it to me. I use the "alcoholic" analogy. You wouldn't offer a drink to an alcoholic.
Wanda