Did anyone suddenly get severe depression / anxiety around a year postpartum?

I did not suffer from (immediate) postpartum depression. The first couple weeks were rough mentally (and of course physically), but despite the exhaustion for the last year, I mentally felt great and felt a deep sense of contentment and happiness.

I stopped exclusively pumping at around 10 months, and unless it was a coincidence, it seems I slipped back into my pre-baby mental state (not depressed, but not feeling extra elevated and happy). I hoped my hormones would adjust, but it’s been 4 months and I still felt just “normal” (not depressed but just always a bit blah - sort of how I felt before giving birth).

Chalked it up to no longer getting the oxytocin from pumping, or perhaps the newborn euphoria wore off. However, suddenly at 14 months postpartum, I was hit with an intense wave of depression and anxiety. I felt I was having a panic attack. I’ve been crying and feeling scared that I may be having some sort of mental breakdown. I’m terrified this will affect my relationship with my baby. I also have a ton of intrusive thoughts and rumination about bad life choices and guilt over not breastfeeding.

I called my friend and she says she thinks it’s due to me not sleeping, and every woman she knows who did not sleep train or had broken sleep suffered from depression. I really do not want to sleep train (baby still wakes a few times a night). Desperate to see if anyone has any insight or shared experiences with any of the above.