May be worth having a read of these articles (links and some text included below).

Given the info in these articles, I would ask your doctor to test your Vitamin D3 levels (25ohD). And if possible B12, Iron Studies and Ferritin as well.

http://drgominak.com/vitamin-d
...."Women bear­ing babies are the ones who are most affected: The rea­son why thy­roid dis­ease, gall­blad­der dis­ease, B12 and iron defi­ciency, obe­sity and sleep dis­or­ders (and there­fore severe headaches) often occur in young, healthy women is because they’re the ones hav­ing the babies. Each baby sucks up mom’s vit­a­min D. Unfor­tu­nately each pre­na­tal vit­a­min has only 400 IU of vit­a­min D, which is not nearly enough to pro­vide for mom and the devel­op­ing baby.
Each baby uses up mom’s D and if she’s not out in the sun enough her D deficit is never cor­rected between preg­nan­cies. Each result­ing child is more D defi­cient and each baby sleeps worse than the last.
Mom also sleeps badly being more D defi­cient her­self with each baby. The chronic sleep dis­or­der over sev­eral years can result in post­par­tum depres­sion and occa­sion­ally psy­chosis; (abnor­mal thoughts and hal­lu­ci­na­tions). I believe that once the sleep is very, very abnor­mal, and the “sleep switches” that keep dreams iso­lated to sleep really start to fail, dream like expe­ri­ences may start to leak into wak­ing life"....

http://drgominak.com/sleep
...."Post par­tum depres­sion may be linked to D defi­ciency pro­duced by preg­nancy and wors­ened by accom­pa­ny­ing B12 defi­ciency. If these dis­or­ders are some­thing we could pre­vent by replac­ing a hor­mone defi­ciency I belieive this should be one of medicine’s major com­mit­ments"....

Not remedies but helpful pieces in the puzzle: early AM sunshine, walking (even a small amount helps), contact with nature (gardening - hands in soil, walks in the woods, parks, beaches....), seeing a counselor. Joining a group of other mothers.

Hard to achieve with a newborn - Good quality sleep in a completely dark room (very hard to get with a baby, hopefully your partner can help out).

All totally breastfeeding safe.

I'm very glad to read that you are seeing your doctor. Depression is nothing to mess around with.

Did you happen to save the placenta? Not a certain cure, but often a big help if you make it into pills and take them as needed to lessen the depression.

If you feel like you are physically drained Eleuthero (sometimes called Siberian) Ginseng is safe to take while nursing, and while not an antidepressant per se, it gives a nice boost to energy levels to make everyday tasks and just getting out of bed feel less daunting, which can be one of the hardest parts of depression. I found it to be a life saver about 3 months after I had my baby and just hit the wall. I took 1 dropperful in the morning and one in the afternoon for 3 weeks and felt relief for months afterwards.

Like others here have said isolation is the enemy, being alone with a baby day in and day out will drive pretty much anyone over the edge. You need to be around other women who have been through this, women who can make you laugh even when you are sad.

Make sure your diet is rich in omega 3's, fish, fish, fish. Those babies steal our reserves to build their own brains like crazy, so extra is definitely needed to maintain our own mental health. If you choose to start taking fish oil, start slowly and ramp up over a few weeks because a sudden spike in concentrated fish oils can just change the nature of the depression if the brain is suddenly flooded, and create serotonin syndrome.

If it comes right down to it, don't fear antidepressant medications, they can be very helpful, life-saving even. Some are safe to take while breast feeding, but if your doctor prescribes one that isn't you can spend a few weeks pumping as much as possible to extend what you have for your child before starting treatment. That said, breastfeeding itself is supposedly a natural antidepressant so definitely talk with a knowledgeable doctor before discontinuing it in search of a cure, and perhaps try a trial of talk therapy for a few months before considering meds.

I agree with the suggestion to get vit D levels checked and talk to your Dr. about supplementing. At some point, have your estrogen/progesterone/testosterone checked too. I waited until my second baby was 9 months old before I bothered to take care of this...big mistake. Good for you for being proactive!

Does your hospital or la leche league have a breastfeeding support group? Sometimes it's helpful to meet with other moms who are going through the same experience/stage of motherhood as you. Also, you can check with the lactation nurses at the hospital to see what other resources your community has. We have a program here that sends voluteers to the homes of new moms once a week for up to 6 weeks. They will help around the house, hold the baby while mom naps or showers, accompany her to her follow up Dr. appt, etc.

Good luck to you and know that it gets better!

Get on in dear, if you get too deep into it really is NO fun. I just went through hell. Here is what helped: Get as much sleep as you can get, going to sleep when baby does, ask for and except help from whoever (find a babysitter to get some hours off, it's worth it), exercise in the morning or early afternoon, start the day with a protein rich breakfast. Supplemments: Vit D3, zinc, B12, Cod liver oil, fish oil in the morning and magnesium at night, no chocolate, coffee, sugars. Get out once a day to interact with the world. Get as much sunshine as you can. Talk about it. Breathe and know that you will make it through. All the best.