My son has been addicted to drugs most of his adult life. After years and years of trying to save him, trying to get him to see that he was killing himself with drugs...I had to let go and turn his care over to God. The alternative was for me to continue to get sicker and sicker myself, running on adrenaline and exhausted every day. He simply was not mine to save.
You've been there and you managed to get clean and stay clean. I pray the same happens for her.
Please do not keep this all inside you. Sharing with your husband and others who probably know the truth anyway will help you unload a lot of the stress. Also, maybe find a meeting for yourself, Al-anon, Nar-anon, CoDA or any number of family or church groups for families of addiction will help you find your balance and cope with whatever comes.
My prayers go out for your daughter, and for you and your family.
Hugs from my heart to yours.