I need help!

I have a problem.  I  keep the peace too much.  Sometimes I wish I could be the person that says what I feel regardless of the repercussions or hurt feelings.  It's my dad's fault.  He crammed it in my head when I was younger. "Think about what you are going to say before you say it," he'd say.  In most cases I agree with him.  But now I think I think about it too much.  Don't get me wrong, I still speak up for what I believe, but I do it in a nice "watered down" sorta way.  So don't piss me off because then I might have to sit down and contemplate what I am going to say all day and then take an hour to type it and delete it and rewrite it because I can't say it to your face because I might say something I will regret later.  ARRRGGGGGGGGG.