I had messed up again annoying her one day, and I had realized a little too late what I've done.
Hello and welcome to the family. I'm so sorry you're going through this and I hope things work out for the two of you long-term. However, that's not the real goal here. The first step is making sure you're okay and processing this in a healthy way.
It's great that you realize you had some responsibility for the break-up, but at the same time you have to give yourself a little grace here. Thousands have posted similar stories (myself included) and the problem ultimately is not you or her...it's mental health and disordered thinking.
In short, she second-guessed the relationship, obsessed over it, and mentally went down a dark path. So much happened "behind the scenes" within her mind that you know nothing about; that's why you're confused on how things escalated so quickly.
Again though, this is a mental health problem.
What should you do from here? It's only been a short time since breaking up, so give her the space she's asked for. If you push, she likely will block you and that's not a good thing. So take this time to focus on yourself, to reset mentally and heal from what's just happened. Find some good habits- working out, going for walks, sports, etc. that can occupy your time. Try to avoid sitting home gaming and scrolling on social media, that leads to depression. You need to get outdoors around people that love you.
Also, take some time and look through the "tools" and "tips" at the top of this page. Start to learn about BPD and better ways to communicate in these relationships. It will serve you well regardless of what happens long-term. Please feel free to ask any questions as well, we're here for you!