1)You don't know how sorry I am.你不知道我心里有多惭愧 。 

2)I went too far.我做的太过分了。 

3)I shouldn't have said that.我本不该说那句话的 。 

4)If only I hadn't done that.我要是没做这件事就好了。 

5)It's me who screwed it up.是我把事情弄砸的 。