Sorry, I'm (really/so/terribly) sorry.
对不起.我感到(实在∕很∕非常)抱歉.
Apologize./Please accept my apology.
我道歉.∕请接受我的道歉.
I feel really bad about...
我对(某件事)感到非常抱歉.
I didn't mean it.
.我不是故意的.
It's all my fault.
全是我的错.
How could I be so thoughtless?
我怎么会那么粗心大意呢?
How can I make it up to you?
我要怎样才能补偿你?
I'll never forgive myself.
我永远不能原谅自己.
Will you ever forgive me?
你会原谅我吗?