I'm... skeptical, and that's coming from someone who finds himself in a situation very much similar to yours.
I have been with my significant other for five years now, and we've been using together for about two years; we're not "needle junkies," as we sniff our dope, but we do lots and lots of dope, and often, too.
I'm under no illusion, however, that this can last and that it will not end badly. Ideally and as a couple, we'll clean up our acts and start to move in a different direction, taking on different projects and setting more life-fulfilling goals for ourselves. It's sort of what we've begun to do, albeit slowly, but it may not end that way... it may just fall apart in our hands before we can even make it that far.
It's sad, but it's true, as there are very rarely, very few things in a self-proclaimed junkie's life that one can count on; it's a life, an existence, almost defined by its rickety, unsure, nomadic-ness where everything seems to be just a hair's breadth away from falling apart. But, at any rate, I wish you all the best, OP, and I hope that things go well for you.