Number one... from what I have learnt, it is normal for some to feel a decreased libido after having a kid. The biggest suggestion really, is talk to your doctor about it first and foremost. Get some blood work done to make sure everything is within normal limits for you (compare to history).
Next, I'd suggest a change in foods. Go more green and natural. If you have a good exercise routine, great! If you don't, maybe start in a yoga class or some other form of exercise. Many mothers just simply don't take or have the time to focus on themselves after haivng kids. And it is important they do. See if you can do some things for yourself. A day at the spa or create a day spa in your home. Or get the girls together for a coffee date and mani pedi day at home with lots of fun appetizers.
And lastly, I don't know if this is the case at all, but have your husband focus on you rather than on sex when he is horny. Then there is no feeling of you feeling obligated to have sex giving your mind a break from the feelings of disappointing him. Massages, candles, cuddling etc...
But above all else, I'd say a doctors visit should be really high up there on your list.
