Isn't Melody Beattie great? Keep re-reading her books! I like that you can just open them up and start reading anywhere and get something new every time.
As far as your partner goes, do you really want a junkie in your house and around the kids? Do you want him back bad enough to subject yourself and your family to him?
Time and space may fix things. You can't make him love you. You can't make him sober. You can't make him want to straighten out his life. He has to be ready and willing and as co-dependents, we want to be ready and willing for the addicts. I know you've heard that you have to let him fall and I do believe that. I've rescued my AH a couple of times now so I'm not so sure he'll stay sober as long as he did the first time when he did it for him. I don't know that I've done him (or us) any favors.
Keep reading, keep posting, keep believing that you can do life without him (and probably better). One day, the lonliness won't be all consuming and the pain will be little more bearable. It's a slow process but you must detach for all of your sakes. Stay busy and go to meetings if you can swing it.