How do I manage this?

I am visiting family that I only see only a couple times a year. I didn't want to come off weird. I wanted to seem normal, not like at home where I count every calorie, don't eat enough, and only eat certain foods and they are few -- not to mention the chewing and spitting done in secret.

    So, I got here this evening and already I feel disgusting, physically and mentally. My brother ordered pizza. I a couple of slices and was TOO full and felt so horrible. Then there was no diet soda, so in order to not appear obsessed, I sipped on one. I felt every calorie, even though I barely drank half. Tomorrow, we will be out and about, and I am certain a fast food restaraunt is in my future. Then there is the whole Sunday at my dad's where I am certain I will be facing trays of finger food.

    I SO wanted to seem casual and nonchalant, probably to take their mind off of the fact that I am too thin, but I am terrified my food issues are going to ruin my visit. I just want to go home where MY foods are. I didn't bring any of them because I actually thought this would be a good way to force myself to gain a few pounds, but I don't think my body is ready for these foods. I know I can order lighter stuff at places, but I don't want to order too light because I am afraid I will get looks that say, "What the h*** is she ordering just a salad for? She can't possibly be looking to lose more weight!"

Help!!!