Problem with being underweight with no appetite

I am 19 years old and I’m pretty underweight. I’m 5’3” and about 97 lbs, and people always comment on how thin I am. I have been pretty small all my life, but lately it’s been getting to my head. I tried to eat more because I want to be around a normal weight (105 lbs), but everytime I eat more than like... 1000 calories, I feel so nauseous and sick. I also have a problem with forgetting to eat because I never have an appetite. It was so bad that my gallbladder started to have complications from irregular eating and I had to go to the ER. The only time I really got enough calories was during school when I would eat fast food a lot. But I would still feel sick after eating that sort of food.

The problem is my family is full of super-dieters, so all our food is either vegetables, protein, or low calorie snacks. I can’t drive so it’s impossible for me to get food other than what we have. To get enough calories (at least 1500), I would have to eat like 10 salads in a day and a lot of protein (which I hate protein).

How can I eat more and NOT be nauseous and sick all the time? I need to gain weight if I want to have kids one day.