It's not hard to get fast at using self-scan, especially if you've worked retail. If many others can be efficient, perhaps consider whether you are part of why it's so slow?
Some of them are quite forgiving and let you go fast, others insist on you placing every item on the scale carefully and still freak out half the time. Depends on the quality of the area, perhaps.
Sure, I'm perfectly ready to admit I'm shit at it. I just don't want this to have to be something I good at.