Asking for help from my mom...? ?

im too nervous to tell my mom how much more I have became sneaky. I had bulimia since 14. I recently went 6 months ed free after countless eating disorder centers. but now its worse than ever. my mom knows I relapsed but not how bad. I am 19 and I need her to send me to an eating disorder clinic. even though I really dont want to stop. how do I tell her before I change my mind?