How do I gain weight?! (READ) I just want the "perfect" body

Okay, so I know what your thinking, "This girl is INSANE! Who wants to GAIN?!" Haha, don't worry I would totally think the same thing! Okay, so I am naturally really skinny, and have a super high metabolism. So, it's REALLY hard to gain weight, and keep it on. The only time I have ever been able to gain weight and keep it was after I went to the doctor and receive a steroid shot. I am so tired of hearing, "Don't you eat?!" (Trust me, I eat.. All the time.) "Get some meat on your bones!" (Trust me, if I could keep the weight on I would.) Anyways, I am 16, and I am so tired of looking like a stick. Seriously, I'm 92lbs with a butt smaller than a babies, and C cup boobs. I just want to have those "assets" if you know what I mean;) I mean, I try to work out to gain muscle, but I just end up losing weight, totally opposite of what I was going for. All I am asking for is a HEALTHY way to gain weight and keep it on. Please comment. Anything helps!