You wrote........ but last week he told me that he was deppresed because of me.... In the book Bounderies (that is a awesome book) Dr. Cloud and Dr. Townsend wrote " Any confusion of responsibility and ownership in our lives is a problem of boundaries. Just as home owners set physical propert lines around their lands, we need to set mental, physical, emotional, and spiritual bounderies for our lives to help us destinguish what is our responsibility and what isn't."
My husband has started working out of town also and it is very hard on our relationship exspecially since it's not all that anyway. You feel like you are alone and think hmm maybe I would like it like this all the time? Maybe that is how he is feeling not realizing that it's not a true feeling because he has a family waiting on him and he isn't single. Alot of times I feel detached from my husband when he is gone and when we argue on the phone it makes me want to be detached, but in the same breath when he is coming home I make sure he has no worries. The house is clean, bills are paid, dogs are bathed, all the laundry is clean folded and put away. I will also do a little something special for him. Last time he was home he called me when he was about 5 minutes from the house and I had him a relaxing bubble bath run w/ candles and wrote I love you w/ my red lipstick on the mirror. I made him feel like I really missed him and it shows gratitude for the sacrifices he is making everyday when he is away from his family.
POINT: You are not responsible for his feelings, he is. Try to be the best wife possible w/ out crossing your own bounderies. Make him ache to be home w/ his family! All you can do is your part. You can't make him change. I love to say SURRENDER-TRUST! Surrender it to God and trust in him to handle it.

Hope everything works out