Bedwetting and boarding school

I'm 15 yrs old and i still wet the bed nearly every night. My parents think im just being lazy so they send me to boarding school, they think the shame and embarrassment will make me stop. i am very thankful as i have a wonderful dorm supervisor who doesn't yell or get angry when i wet, and understands that its not my fault. I have been to the drs and all sorts of different people that were suppose to help me stop, but nothing has ever worked for more then 2 months. All the other girls in the dorm are understanding and don't tease me, and i'm very thankful for that as well. I'm also very thankful for drynites as that means that i no longer wake up soaking wet and cold and it doesn't become 'public news' when i wet the bed.