I am in the same position as you! I'm 20 and was diagnosed about a year and a half ago. My parents have come around, but at first my dad got personally offended when I wouldn't "just try" something with gluten in it, and my mom thought I was so rude for not eating food with gluten that she made. I feel your pain. I have been struggling with weight gain too, and I recently went completely insane and went to every single fast food place and ate all the gluten possible for about a week. It has been easier since I moved out of my parents house and buy my own food because bread isn't always staring me in the face.
I still have some stomach issues but they have improved A TON after I gave up dairy, which is another added restriction but it was definitely worth it. I lost about 10 pounds and I don't bloat nearly as much any more. Can you go shopping for your own groceries? That would probably help a lot!
I cant imagine having no support though .
I have found that replacement gluten products are not the best and almost every time they leave me crying over my food and how much I miss the gluten. So I just try to eat dishes that are gluten free to begin with like meat and potatoes, and fruits and vegetables.
I tried to take it as an opportunity to get healthier and that really has been a blessing. I eat a ton of fruit which helps with my cravings and it helps with weight loss too. Eating out is a particular challenge that I haven't gotten used to. I was always the girl who never made any trouble for the waitress and now I have to drill them with questions about what I can eat and even then, they think I'm rude or just making a big deal out of nothing.
I'm sorry I don't have many suggestions, I just feel the same way and am really struggling with this disease.