I’m so sorry you’re going through this.
My initial thought is that maybe you need to find a different type of job or a job in a different field. The ADHD brain is motivated by interest and urgency, not be importance like neurotypical brains. That means, if you find the job tedious or aren’t invested in what you’re doing, you will lose focus and interest and that’s when mistakes come in.
As well, anxiety can greatly diminish cognitive functioning. So, when you’re really anxious at work, as you understandably are now, you’re ability to do well is greatly reduced.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism