Weight Gain

So many people want to lose weight, and that's great if that's what they want but I've always had trouble with my weight. I'm naturally very skinny and i have a high metabolism. For a short period of time, probably a month I had a really tough time with eating though and so ever since then I can't gain much. I wasn't able to in general but that made it worse. I would love to gain at least 10 pounds. I would still be underweight but that would make me so happy. I'm currently 102 and about 5'7" and I'm vegan. If anyone would help I'd love it. I hate the criticism that I should just be lazy and not care what I eat. I don't want to jeopardize my health like that. Plus eating junk makes me lose weight for some reason. Thank you if you have any suggestions