Anorexia and sports, what will my coaches say?

So, here's the thing. I'm a sophomore at a small high school in a tiny town. I am basically their best athlete already in track and volleyball, and along with being a national qualifier in academic events and having a 4.0 GPA, there is a lot of pressure to be perfect. Pressure I cracked under. See, about 8 months ago, I started cutting food and stuff out of my diet so I wouldn't get out of shape in the offseason. One thing led to another and now I've lost 15 pounds, which doesn't sound like much, but now I weigh 108 pounds with a height of 5'8 and eat only 800 calories a day with day long fasts in between. I have a doctors physical coming up, and I am concerned I could get busted there because along with my weight loss, I haven't gotten my period in 3 months. (trust me, I'm not pregnant) The thing is, part of me actually wants to get help but is terrified at what her volleyball and track coaches will say. I'm terrified of disappointing them because they are almost like family to me. What will they say if they find out I've been diagnosed as anorexic?