I had horrifying PPD. I think Lexapro takes a good week or two to kick in. I didn't have any help when I went through it but I'm finding that there's a specific form of meditation that's been helping me. The Chopra 21-day challenges from the summer (Freedom to Love series) and fall (I think it's called "Abundance") are done in a way that helped me learn how to meditate and although it took me at LEAST 9 days into it before I could actually stop thinking about all kinds of other things during the meditation part, I stuck with it and I have to tell you that it changed my life.
It may do enough to take the edge off for you before the Lexapro kicks in.
Beyond that, see if you can get your support network in place. On one hand, having people around to help me TOO much made me (personally) worse. At the same time, I needed to not be alone. It was hard to find a good balance, but start there. See if people are able to come visit a bit if you're up to it. If you have any kind of community (Holistic Moms chapter, LLL chapter, church group if you belong to one, etc.) tap that for this. You don't even need to divulge your PPD if you're not comfortable, just note that you're feeling like a fish out of water and need some outside contact.
Hugs, mama.
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