I'm not much help, except to say that I feel your pain! I was hoping to avoid any more pregnancy and PPdepression because I dealt with a lot in my first few months of pregnancy. Now I am suddenly experiencing crazy hormonal swings, ups and downs, no energy, tons of crying for no reason - all of which are normal for the 3rd trimester, but all of which mirror my depression issues when they come up. So so frustrating!
What I am trying to do for myself: improve diet (I turn to sugar and junky carbs when I"m low, which is making me feel especially unbalanced and exhausted now that I"m so very pregnant - like, within an hour of eating cookies I feel terrible, yet I keep going back for more) - focusing on veggies and lots of good protein. Slow down - things are taking me twice as long and even then I only have energy to get about half as much done as I normally would, and then I beat myself up with "but so and so worked up until her due date, what's wrong with me?!" etc. Take naps and rests when I can. When I start feeling that panic of "I can't deal with this", I'm trying to breathe into my belly and just be okay in the moment I"m in instead of trying to figure out how I"ll have the energy and strength to make it through the next months, birth, and caring for an infant.
Mostly I am trying to ask for help when I need it, forgive myself for when I need breaks, and remember that I will not feel like this all of the time - that there will be good times too. It's hard but I"m trying to learn from it.
That said, make sure you also are having times when you don't feel as bad - if it turns into an all-the-time, won't-go-away depression, ask for help!
I hope you feel better, and, yes, here's hoping we can avoid PPD because we're dealing with all this stuff now!