How do you let go of loving an addict?

Maybe you can separate yourself at least for now. If they get to the point where they are trying to help themself then you can step back in and help them through. At least if you have In your head that you will be ready to help again when they are ready you won’t feel so guilty for stepping away. Sounds like you have done what you can and should give yourself credit for your effort rather than feeling guilty because in the end they need to accept the help. Not your fault at all. I wish you both well and good luck!