a'pcha
A loud, angry, or excited sound you make when life hits you with a surprise or a problem. It's like your brain short-circuited.
A'pcha! My teacher gave me a pop quiz and I didn't study.
A'pcha! My dad tried to fix the Wi-Fi and now it's broken.
A'pcha! My crush asked me out and I said yes... then remembered I had a test.