I just want to know why I’m so depressed

It seems like every months right before I get my period, I get really depressed. And I know that this is a normal symptom for some women, but I mean REALLY depressed.

Like almost suicidal but not really. My thoughts are more like “I love my life but eh, I really don’t feel like being here right now.”

I’ve struggled with depression ever since I gave birth in 2016, but it’s gotten a lot better. It now just shows up before my period. :(

Just wanna know why it’s so severe and if anything could be done to stop it from happening every month.