Should I or shouldn't I?

There are a lot of times and situations in our life when we are very tensed and are having a confrontation with someone. If it is direct confrontation then its easy, you can say what you feel like but what if it is not direct and you just keep thinking whether you should say something to the other person or not. If you say something then you will be cribbing about things and will break the "supposed" harmony in the relationship but if you don’t say anything then you will yourself never be at peace and it will affect your relationship anyways.
I have made many friends in my life...some have been lost due to distance, some due to lack of communication, some I have lost because i pointed out something I didn’t like and some because I did not say what I felt. Life is full of conscious and unconscious decisions that we make. Moreover what we think to be true might not be the reality. We see things from our perspectives and feel that we are correct. Even if we realize that we are wrong we sometimes site lame excuses to justify our acts.
Do we ever accept our mistake and agree whole-heartedly that we were wrong. I have heard (and even said) some things after a fight which says that "I am sorry" but it means something else. It means that "though I am saying sorry but I don’t mean it". It means "I want this altercation to end but I still think you are wrong". Is honesty always the best policy?
I personally feel that we should say what we feel. I have been in a lot of trouble with everyone for speaking my mind. I am not rude to people but speak my mind when I have to. If we change ourselves just to gel in with the crowd then we are losing a part of ourselves. It is important to say what you feel as if you don’t say it then how do you feel others to know about it? Whether it is expressing love for someone or discontent, say it and make peace with yourself (atleast!!!)