addiction/ eating disorder

im 16 years old, yes i know im young but please no rude comments. i started abusing prescription drugs about a year and a half ago due to the trauma of being abused as a child physically, emotionally, and mentally. nobody knew about the drugs until i was really messed up on day at the end of october.. tried stopping but relapsed in december still doing drugs till this day i desperately want help but i really dont know how to confront my mom. i also have an eating disorder i eat nothing all day and if i do its a little bit of fruit and i still feel horrible about myself im starting to look really bad and i just wanna be my old happy self.. i wanna be able to get help but how should i tell my mom?