<human>: Give me the gist of the text in a nutshell

F/20/5'2''/120
So heres the deal,
I never gave a thought till how I ate until last october when my bmi hit overweight the first time at 128. This stuck me and in about 3-4months I lost about 18 pounds at school. I've returned home for the summer and am on a serious nutrition kick. It's all I think about, all I crave, and when I eat unhealthy things, I feel guilty and I physically feel bad. I get an upset stomach every time I eat something like pizza, or fries, cake, exc. The problem is my family eats however they please. I do do most of the cooking but every once in a while I get a surprise. Like tonight for instance: I came home at 9:30pm and had a pizza waiting for me that someone had ordered-just for me. It makes me feel so terrible I could cry. I've worked hard to get where I got and this is exactly the kind of food that now upsets my stomach and makes me feel guilty. What can I do or say to my family without hurting their feelings? I already get comments like "she doesn't eat carbs" directed at me, even though I do, and I can tell that they are frustrated, but so am I. I apologize if this isn't the subreddit for this, or that there is a better one out there, but I would greatly appreciate some feedback and help.
Thank you in advance,
LandAubrey
<bot>: What do I tell my family when they make or buy me unhealthy things and I can't/won't let myself eat it because of guilt and a potential upset stomach?