Meds and breastfeeding/side effects

I've really been struggling lately. I had my 4th baby 6 weeks ago. Like all new moms I'm exhausted. However ,I am so void of energy it is difficult for me to even make lunch for my other children. Every morning I wake up and I think about all the things I should do and I just cry. I'm still on maternity leave but I'm a teacher and will be going back to work in a few weeks. I also am leading our school science fair this year. I don't even know how it's possible for me to do it when I don't have the energy to Simply bathe myself. I have an appointment with my doctor next week and he had suggested that perhaps I was suffering from Baby Blues. I suspect he'll bring up medication, but I'm hesitant because I am exclusively breastfeeding and I'm concerned about the side effects. I would love to hear other's experiences specifically with energy and just feeling more human before and after medication or homeopathic remedies.