I think I misunderstood and have been mispronouncing the word all this time.
I think I've been saying that word incorrectly for a while now because I misunderstood the proper pronunciation.
1) I think I misunderstood and have been mispronouncing the word all this time.
「勘違いでその単語をずっと間違えて発音していたよ。」
I have been mispronouncing the word all this time で「その単語をずっと間違えて発音していた」
2) I think I've been saying that word incorrectly for a while now because I misunderstood the proper pronunciation.
「正しい発音を勘違いしてずっとその単語を間違って言っていたよ。」
I've been saying that word incorrectly for a while now で「ずっとその単語を間違って言っていた」
ご参考になれば幸いです！
日本 
