My marriage was definitely falling apart. But it wasn't just the lack of sex, it was the lack of money. Before we had kids we had a pretty good sex life. However, I was gradually becoming less active because of the stress I was under about money.
I have three kids, ages 3, 2, and 7 mo. It is a wonder that I have three kids being that I rarely have the urge to have sex. Most of the time I just did it to get him off my back for a while. I got to the point that I hated it because I felt like it was another job in addition to the three I already had, not counting the kids as one job.
I, too, suffer from depression but have not gotten on any medication. My depression didn't come from having children, more like life circumstances, Family deaths and a failing marriage. Even though we are back together and we are doing okay, even though he is not working, I still find myself getting into those emotional states that make me tired all the time, not wanting to eat, crying about every little thing, and even short tempered sometimes.
I read most of the responses to your request. I agree with the exercising. It has made me feel a lot better and have more energy. I also recommend finding someone to talk to, counseling. I talked to my Preacher at church for a while there, it made me feel more confindent about myself. I felt like it had lifted some weight off of my shoulders.
Life is tough on us, and it effects us emotionally. We, as women feel like it needs to be fixed. Then men try to make you feel worse about the way you already feel. Try to make you feel like there is no reason for your current feelings. They do not try to understand you, they only understand that things are not the way they want them to be. Like getting sex on the regular.
I hope that you can find a way to get through all of this in one piece. If you want your marriage to work through this, your husband needs to get emotionally involved and you both need to go to counseling, if you can get him to go.
God bless you with the strength to keep going.