What Foods Can I Eat To Increase My Weight, Immunity, And Fertility When I Am An Underweight Vegetarian With Anxiety?

Hi doctor, I am 27 years old. My weight is 48 kg, and height is 5.8 feet. I am a pure vegetarian. I need to increase my body weight. I am suffering from psychological problems like anxiety. I am not diabetic, BP is normal. I do not smoke and drink. Please suggest foods to increase weight, immunity, and fertility. Kindly advise. , faq : Q. I am 28 years old and my weight is only 48 kg. What should I do to increase my weight?