Hanna, I know your heartache and fear and I am sorry you are going through all this.
My son is my foster son and his entire birth family was addicted to something. We thought if we gave him love and guided him to living a better life, that he would avoid the addiction that had been such a normal part of his early childhood. He spoke against drugs, swore he would never touch them...and then he did...and the rest is history.
My husband and I tried for years to save him, and yet after many rehabs and chances for a new life through employment and support from us...he still chose a bad path and today, many years later is is a middleage adult who still is in and out of the revolving door of addiction/recovery/relapse.
What I learned was that there is no way to help him when he won't take the actions to help himself. Trying to help only enabled him and probably prolonged his journey. Somewhere along the way, our home became a war zone and I lost sight of who I was or what I wanted from life. I didn't KNOW how to live any differently than I was living.
What helped us find a happy, healthy better way of living was to go to meetings. CoDA was my home group, Al-anon was there for me too on a regular basis and through these fellowships I learned to let go (and what that really meant) and to learn to live in a healthier way.
Today I find beauty in every day. Today I am led by a spiritual purpose and find peace in even the worst of times.
My suggestion for you and your husband, if he is willing, is to find meetings close to your home and attend regularly. Also, a book "Codependent No More" by Melody Beattie has helped many of us learn about why we do what we do and how to find a better path for US, no matter how our addicted loved one is doing.
There is a lot of information in the "sticky" threads at the top of this forum, maybe take time to read a few and see if they don't help you too.
My prayers go our for you and your family.
Hugs from my heart to yours.