How to I gain weight the healthy way?

Well, first off you're still really young so give yourself a break and understand that it may take a few years. In the meantime, eat small meals frequently during the day. Also, protein shakes and lifting weights also works. And keep in mind: we all want things I can't have. I often wish I had less and a more model-esque body, but all I can do is work out and be happy with what I have.