Selective Eating Disorder...IMPORTANT!?

i recently found out about Selective Eating Disorder, but have been extremely picky for as long as i can remember (pretty much my whole life). i read that normally, people have just a few foods that they specifically refuse to eat/don't like, but people with SED have very few foods that they actually WILL eat. i have this problem. there are not many things i like, and things i do like i eat all the time. to give you an idea of how picky i am- i can't eat any kind of sandwich because the different textures freak me out, i don't like any seafood, i pick my foods apart a lot, probably about 90% of my diet is pasta and whatever i put on it for taste. it's really hard for me to find things i like to eat at school because i'm so picky, and always lose a couple pounds when i'm there (i'm already about 19 pounds away from being considered underweight...i'm usually about 15 pounds from underweight at school). what should i do? i don't think it's a super serious problem (ie- life-threatening), but it is really difficult to go out to eat, or to eat in a healthy way. also, i'm worried about when i have kids because i don't want them to follow my example =\