I had pretty bad PPD after i had my daughter, and by the time i realized that i needed the medication i was already going off the deep end. The meds hadn't had a chance to kick in yet and i just felt crazy. Not that i wanted to hurt my baby, there is a difference in PPD and Post Partum Psychosis. I hated being a mom, felt guilty that i hated it, and wanted to scream every time someone would ask me how much i loved motherhood.
I began to behave in some pretty self destructive ways, and was lucky enough to have some women in my life that stepped in and helped until i could get it together. My medications began to work, but i also went to therapy and it helped a lot. It helped me to give myself a break and realize that despite the way i felt, i was doing all that i could to put my daughter's needs first.
I was exhausted as well, and doing the simplest task to all the effort i could put forward. I would make an appt ASAP, it takes a few weeks for the meds to fully work.