how to put ON weight???

So glow users, I hear a lot of questions on how to lose weight (on and away from glow) but MY question is how do you put ON weight? I'm a 17 y/o and I weigh 84lbs/38kg/6 stone, 4'10 1/2.
I really want to put on weight and grow and tone my figure. I'm happy with my body but I want to put on weight because so many people tell me I've lost weight or that I'm too skinny (I used to be 43kg, I assume my depression and anxiety have affected my eating habits), it does make me feel insecure but personally it doesn't look nice that my bones are visible (on myself, not other people) and I just don't know how to put on the weight! Even to get back to 43kg or put on the slightest weight would make me happy, I just don't understand because I eat so much food??? Does anyone else have this problem? Please no comments like "stop complaining about your weight" because I've been trying for ages and it seems like my metabolism just isn't having it 😂😞
EDIT: my boyfriend just pointed out to me that's actively do karate and I forgot to mention that I'm a vegetarian, I stopped eating meat and fish in July whereas before that I used to eat a lot of red and white meat