Find out what is going on. You need him to open up. Maybe he is stressed? Maybe unhappy about something? Read my reply about communicating a few replies ago. Learn how to communicate and learn "how to fight". Getting things in front of both of you and dealing with them is the best form of passion. Plan some alone time. Use the one response about the candles, roses, bedroom set up mentioned before. But, as you can see by her response as well, talking about each other's needs and issues, understanding the issues, dealing with them by comprise, and then getting over it and moving on are the keys to great love and sex. You are both missing the emotional love more than the physical. Try something new and exciting. Dress up, role play, change atmospheres, get a hotel room, if one of you is interested, things will work out.
Try to stroke his intellect. Men need ego boosts. Our ego is very easily hurt. Hold his hand in public out of the blue. Give him a kiss for no reason. Compliment him. Tell him how thankful you are for what he provides you and the family. Men that feel like they are real men, worry about everything (money, whether the family is happy, whether they are doing a good job at work) You will be surprised that he will start returning compliments as well. That makes you closer and lends to a more passionate relationship and therefore, more sex. Hope this helps.