I recently watched a medical programme about sex and pregnancy. I found out that it takes at least 6 months after you stop breastfeeding to get your hormone levels back up to the prepregnancy sex drive you had before. I'm not sure if you are breastfeeding or not. But the fact that you have two children and one of them is under a year leaving you worn out doesn't help your drive right now. I agree with Fee that for the sake of your marriage it is worth the effort. It is a good idea to talk to your doctor to see if there is a hormonal imbalance.