@rainysunflower I had the hard kid first, had two solid years of PPD after each kid, and absolutely 100% regretted having a second for two solid years after having him. It didn't help that he was born six weeks before Covid hit.
Currently they're 6 & 3 and life is only just recently starting to feel liveable. Not fun, not manageable exactly, but I'm also not severely depressed even though I have plenty of days of complete overwhelm. It has not been good for my mental health though, and has been a huge marital strain (we've been in therapy for nearing two years and that's helped). Tranquil is not a word I would ever use to describe our house, lol.
So yeah, I would just say it is a LOT and even my parent friends who like having kids more than I do all said the first year of 1-2 was hellish.
That said, my second kid was easier than my first, which helped. I do know a lot of people who've had the opposite experience (easy first who tricks them into having a second, so they have a more typical baby but are floored by how 'hard' it is).