Wǒ zài qìtóushang shuōle yìxiē bù gāi shuō de huà.
I said some things I shouldn't have, while I was still angry.
Tips
usage
Always pairs with 在 — 在气头上 ('be in a fit of anger'). The 上 is read in neutral tone (shang). Implies the anger is fresh and will subside; classic advice: 在气头上别做决定 'don't make decisions while you're angry.'