hormones after giving birth

My second child I'm not sure what is going on but I have no desire to have sex. I am exhausted because I work full time and he still does not sleep through the night. I try to get into it but at times I don't even want to be touched. My husband is inderstanding, but I feel so guilty about it. Has this happen to anyone else? It didn't with my first. Could it be  postpartum depression? I'm trying essential oils for my hormones. I just don't know what to do to get back to myself. Help!