Some more information would be helpful. How long has he been gone? If he was transferred that implies this is a permanent move and he will not be returning home? How far away is he, a few hours drive or a plane flight? How often do you see him?
I too would be worried about why he wasn't calling every night like he used to. However, if he feels that when you call that you are complaining, try talking about something different. Ask him about his job? Tell him what's happening back home. Tell him you miss him.
You say the little you earn helps the family. Is the little you earn covering the expenses of him living away from you under a separate roof, paying additional utilities, etc. What about the emotional cost for each of you and your children?
You don't mention your current living situation. Do you own a home, rent? Are you locked into a lease?
What should you do? Sit down with hubby and have a long discussion about the needs and goals of each of you and how they affect the entire family. Have all your financial information in order and see what you can do about being together.