Struggling with Being Underweight

I also am and I am vegan but I just had to reinclude chicken to put on weight. I think it's working, but too early to tell. I suppose you have already tried higher protein and fats, right? Cause that helped me lots after losing weight, but also the reason I lost it was from birth control, so I had to stop taking hormones. Idk if that helps, but if you want you could check hormone imbalances with your doctor. I know people who had issues due to natural hormonal imbalances.