This could be a bit of a difficult period for your relationship, but you can come through it stronger and more closely bonded in the end, if you really work to understand the lessons of this transit. Fundamentally, this period -- which will last nearly a year -- is about coming to terms with all the pretty illusions you both hold about your relationship. You've both got each other and your bond up on pedestals, to some extent, but now you're being pushed to face your projections and come to terms with the truth.
Does this have to be a depressing process? No, but it might be one all the same, especially if either one of you is overly committed to looking at the relationship through those famous rose-colored glasses. If you find yourselves feeling disappointed by the reality that exists between you, you might think about why that is. Why are your fantasies of how things could be more important to you than the truth of the way things are? Try not to get too discouraged as reality rears its head in your relationship. This period is actually a necessary one, as it will help you separate what's possible between you from what's not.