body weight problems

I've always been really skinny, but in the past year I've lost a lot of weight. I used to be in track and it was he only time I was ever at the right weight for my height. I'm about 5'6" and I weigh 106 lbs.. at the beginning of summer I weighed about 112 lbs, but I've noticed that even if I eat several meals a day, I continue to drop weight! Is there any way I can gain a little bit in a healthy way? I'm worried that I may end up with malnutrition or too skinny and that scares me a little