Some examples - 
1. I'm learning to drive and when I was in traffic I got really worried about taking a turn and couldn't focus on anything because the individual things moving (red car, next car, grey car etc.) and sounds (an airplane flew overhead, some honking) made me feel really overwhelmed.
2. I'm waiting at a doctor's office and my appointment is late by like 10 minutes, while I wait now I'm distracted by and overwhelmed by the many hospital sounds - wheels turning, phones ringing, people talking, walking, doors opening/closing.

I can't think anymore at this point and I'm driven to tears. Normally I stop and breathe but e.g. when I'm on the road I find it really hard to come back to the task at hand and make mistakes that could be dangerous?

Any methods you use to cope would help! Tbh, knowing other people deal with this too would help just as much :)