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?