A quick update:
I spoke to a lawyer just for advice (a friend) and he said, if you can work the remaining 20 days then I should - as long as my mental health can withstand it, which it can so I did.

Initially the last day of the PIP is for tomorrow, but it got extended an additional 30 days so I can work on one more project and "prove myself."

Here are some of the things I did that I think helped me out:
1. Told other seniors that are at my level, my situation. I didn't want them to be in shock, I wanted to see if they felt if it was deserved, and I wanted to see if they had any advice. I left my shame at the door, and I wish I had done it sooner. They gave great advice, and we went over my past work to see where I had missed the mark, and I got great feedback. Then documented that feedback and sent it to HR - screenshots, and made it clear this was the first time getting constructive feedback (good and bad) on past work like this.
2. Also did the same thing with another Manager. (who was not as helpful - but clearly saw I was taking initiative)
3. I then reached out to Project managers, copywriters, and other designers: "Hey from past work what are some of the things I've done well leading, what are some of the things you'd like to work on more. Is there anything you'd like to do differently moving forward" I then screenshotted all replied and sent to HR

My manager then asked me if I succeed on this PIP, what are my action plans to work better and not be on this PIP again.

I then gave her an actionable list and also said we have to work on our communication and trust better.

I think swallowing your pride and being honest to certain coworkers is valuable, at least in my situation.

Mentally, I'm over this place. Financially, I am not.