Thought I was reading my own thoughts for a second there. I too went through a long nasty spell and like you directed my anger at in-animate objects. (walls, doors, etc) These episodes would followed by feelings of utter despair as I would realise the chaos I had caused. A vicious circle creating a deeper depression.
Anyway, my wife too starting suffering with bouts of depression and we needed to take care of that as well. Like you, I feel I am responsible for this happening to her. It is good that you "poured your heart out" to her and yes, she will trust you with her deepest thoughts and feelings again. It just may take some time.
about marriage counseling. We did go to a marriage counselor and she wanted my wife to go to personal counseling first. It took a while but my wife did finaly get personal counseling for her depression. After that we had one appointment with the marriage counselor, who told us we didn't need her. Once my wife and I had dealt with our personal "demons" life was much better. We could talk again and we could love again. It has been a couple of years of a good marriage again.
Encourage your wife to see a doctor and maybe even a counselor. She will benefit greatly from doing so and so will your marriage.
I hope this is of some help to you.