I am an OB/GYN with 10+ years of experience (and father of 4) and I want to tell you that what you are experiencing is completely normal.
First of all, with regard to the physiologic changes associated with breast-feeding. When you are breast-feeding, there is a suppression of your normal cycles, lower levels of
estrogen, and resulting / temporary thinning and fragility of the vaginal 'skin'. This results in painful intercourse, and, not suprisingly, a decrease in libido.
Also related to
hormonal changes while breast-feeding, libido is suppressed. This would make sense from an evolutionary standpoint - it would not be advantageous for the mother to be getting pregnant while taking care of a newborn.
There is no medicine that you can take for your libido. Things will continue to get back to normal further once you have completely stopped breast-feeding. Second, it might be worth a trip back to your OB/GYN to re-examine your bottom and make sure everything has healed correctly (I am assuming you had a vaginal birth). Finally, I am trying not to underestimate the strain that a new child has on a relationship, but it does! Ask your husband to be patient. For some women, a visit with a
psychologist also helps.
Good luck!