If you (or I) remove the second "stop" from your second line, the syllable count will be spot on. Syllables are how many parts a word sounds like it has when you pronounce it, and seven at what you need in the second line. Larger words like suffering (pronounced as "suf-fer-ing") are bound to have more than short ones like stop (pronounced simply as "stop"). The trick is to note what the longest word you're using is and how it sounds when spoken out loud, and then work things from there to meet the syllable count for each line. In this case, you were just one word/syllable over in the middle line again.
Also, contractions usually count for the same amount of syllables as the word they've become part of. So "it's" is still just a one syllable word.