Struggling at work - looking for tips.

I need to add my 2 centavos.
I have been a service manager and shop forman for a couple places (Goodyear, Aamco Trans, Taylor Rentals and Midas) over my years and need to tell you.
That if I had a coworker like you I would LOVE it.
Very attentive and typically perfectionist people with a mission for what they want ASAP.
ADHD people can pay good attention to doing things they love to do, and you seem to have that love for what you do (or do you do it for a job an not really like it?) cause it really matters in your situation.
Also, self doubt is the killer of minds.
Everyone makes mistakes and you will continue to due so on occasion, but don't let it tell you that you are not good enough to be out there and do it.

Dude, my wife tells me that she might not think I'm capable of some stuff here and there and guess what?
Sometimes she's right, and most times she ain't

There are a lot of good responses to this thread and some great info, so you should take the info that works for you and implement it.

BUT by all means keep in mind that you can do it and you know it, because otherwise you will already be defeted without even trying.

Slow down a little and go through each event of what the job is in your mind and "Get er Done"