When life proves most challenging -- to the point where hope seems lost -- I find it useful to expand my awareness past my individual problems and turn my focus to a broader perspective... one that helps remind me of what is important in life. Doing so serves to awaken the strength you have within so that you may use it to pick yourself up and continue moving forward with renewed vigour.
With that said, I wish to share this quote with you:
The deeper that sorrow carves into your being, the more joy you can contain.
Is not the cup that holds your wine the very cup that was burned in the potter’s oven?
And is not the lute that soothes your spirit, the very wood that was hollowed with knives?
When you are joyous, look deep into your heart and you shall find it is only that which has given you sorrow that is giving you joy.
When you are sorrowful look again in your heart, and you shall see in truth that you are weeping for that which has been your delight.~ Kahlil Gibran, 'The Prophet'
While your current situation may be quite painful, I encourage you to do your best to endure it. Don't "go dark" to escape the pain, for only when you maintain your awareness will you have access to your true power. Experiences such as these serve to awaken the dormant resources at the innermost levels of your being -- resources you probably didn't know existed -- so that you may come out at the end as a more conscious human being with greater capacity.
I hope both you and your partner reach a resolution that works out to be the best for both of you, and may you have the courage to keep moving forward, regardless of what comes your way.