You and your wife both have my prayers, kula. The fact that you're willing to make this marriage work,
despite how you feel, speaks loads about your basic character.
To love is a choice we all make; many a marriage (including my first one) has failed because one partner decided
not to love the other person.
I can't tell you how to love your wife, but I can tell you how it feels to live with a depressed, miserable spouse. It's a horror beyond anything I have every experienced. There's nothing I can do to make my spouse smile, much less be happy. His days are spent at work, his time off is spent hiding in video games, or computer programming, or in a moody, angry/sad silence. My touch doesn't affect him, and my voice doesn't bring him comfort. Far from taking joy in his children, he shuns them. Because of the lack of affection from their father, they turn to me for that "good touch". They miss their daddy.
As a woman, my heart aches and I sometimes feel that my days would be better spent elsewhere. As a Christian wife, however, my vow includes respecting, loving, and supporting my husband no matter what. I've had to turn to these forums to take a more Christian perspective on my husband, instead of listening to the world's view and leaving him at a time when he so very obviously needs me the most.
Your wife still loves you, but your depression will take a toll on her, as well. Love can't be killed, but it
can be starved. You need to feed your wife's love in order for it to flourish. Love her as Christ so loved the church....By beginning with the little things. Cherish her, look out for her, don't forget to thank her for the little things, and compliment her occasionally. Touch her, even if it's just a cuddle. A woman was designed by God to need these things from her spouse.
For you, please look at the good she does in your everyday life. Notice when her hands do the laundry. Notice the meals she cooks, how she moves, what she does to please you. Love grows when we see the good in a person's heart. Don't look at her negatively; negativity will only make your life seem worse, and does no good. Don't cut her down or belittle her, because she needs your approval and depends on that validation from you.
Also, counseling for how you're feeling would be a very wise idea. What you're feeling needs to be bounced off of an objective third person, and the counselor can give you guidance as to how to proceed in making the marriage better for the both of you.
Above all, PRAY. Read your Bible. If you have a concordance or the Sword Project (a Bible program), look up what God says concerning marriage. You'd be amazed at some of the things you find.
God bless you in this journey, my friend.