Many people would envy you. Eating everything and not getting fat is the dream of many girls. You can take various dietary supplements. But they should only be taken if you train on a regular basis. I think you need to make a meal plan. Look on the Internet what food is the most high-calorie and eat them. Or you can contact with people who are engaged in drawing up a meal plan. When I was losing weight I asked help from
https://www.modernfit.com/programs/noom/how-noom-stacks-up-vs-weight-watchers/. And thanks to their nutrition plan, I reached the desired at two months later. Maybe they can help you, too.