Don't be too hard on yourself :-)
Mummabear16 - my midwife told me that when you are breast feeding your body releases a hormone that dampens the sex drive which is natures way of naturally slowing down the reproduction process so soon after having a baby. So this could be a reason... if you are breastfeeding...
Piscesmama, do you have family that could look after her for the night so you guys can have some alone time? Or can you both pull a sickie one day during the week :-)
Also, sometimes my daughter wakes in the night, I hear her on the monitor but I wait to see if she will go back to sleep, 99% of the time she does so I just go back to sleep as well, you could try that to get a little more sleep...