I'm sorry for all the rude things I've said and done to you.
I apologize for saying and doing rude things before.
I'm sorry I've been so rude to you.
全部を英語にしたらこうなります：
"I've been thinking about it a lot lately, and I've been wanting to apologize to you, but I haven't been sure how to say it in English, so it took some time to write this apology. So it might seem like it's coming out of nowhere, but I'm really sorry for all the rude things I've said and done."
「今まで」とはもちろん「until now」とかの英訳はありますが、この場合では「before」の方がいいか、ただ現在完了を使うだけでその意味が通じます。例えば：
I'm sorry I've been so rude to you.
I'm sorry I haven't been nice to you.
I'm sorry I haven't cleaned my room.
など
I apologize for all the things I have said until now which were not very nice.
こんにちは！
ご質問ありがとうございます。
"I apologize for all the things I have said until now"＝「今まで私が言ったことに関して謝ります」
"which were not very nice."＝「それらは失礼な発言であった。」
☆ニュアンス的には、"apologize"の方が"sorry"よりもフォーマルな言い方になります。
ご参考になると幸いです。
アメリカ合衆国 
