I let my training wheel show

My gawd, it is times like this that I wish I smoke. Yesterday, I showed the third wheel on my tricycle. I wish I hadn't lost my cool and sent that email. You see it is like this: My boss asked me to sent a second news release to this person, highlighting the fact that it is the same release but with a slightly different twist, sorta like announcing the end of something. Anyway, I sent it and then I got a reply from this person asking me if I'm "aware that the articles on X topic came out in the newspapers last week" and "please get a copy" from a certain party. I just saw red. So I sent back a reply featuring a 'grateful tone' with an ungrateful bite by pointing my wheel at a certain party though there was no name mentioned, for the reason for sending the news release. In short, I pointed my finger at someone else. When I came here, I noticed that this is a practice that is quite prevalent and I can't believe I did it myself. I feel horrible after I pressed the Send button. My boss came over to tell me that is not how I should have done it and I know that. I wished I hadn't let my temper rule my actions. There is no way I can come back from this. The only thing I can do is to grow up faster by learning more. I can't believe I showed my boss how childish I was yesterday. *sigh*