Postpartum struggles!

Is it normal to experience the whole “postpartum depression” FOUR months after giving birth? Or have any of you experienced this & have any advice?

The first two months my daughter was here life was great. Now things seems to be taking a turn. At least I think. I do have a lot of outside stress contributing & my daughter is absolutely amazing so I wouldn’t say in any way it’s her. I never thought I even had postpartum depression until I read the other day that you will feel super happy for a moment & the next your world is crumbling beneath you. & it will go on for weeks not just a few days. It wasn’t until then I realized that’s me the last month or so🙄 I’m only on my second period after giving birth at this very moment. So I attributed my moodiness to my body’s hormones trying to get back to normal. I don’t even know if I’m actually experiencing postpartum but lately I just wanna rip my own hair completely out. I feel just as bitchy as when pregnant. It never ends🙃

Why is this all occurring 4 months later? I thought my body would be pretty much almost leveled out by now.

First time mommy here!