how to be myself?

Okay so i read it everywhere that just be yourself and you are unique..i try to stay myself most of the time..my strenghts being that im a very independent girl im ready to take on responsibilities im a workaholic and competitive so i dont easily get washed out by challenges i know when and how to crack a joke..but im able to show my self to only those whom i know and i find this so i dont know how to describe it..i do wanna feel the freedom to be me whereever i want to despite the surroundings but im held back always thinking what will they think what is the right thing to say how to sit how to stand how to make an impression because of the "rules" that we should abide if we are i an office or hospital or with your teacher or with your mother, and most importantly how not to show my anger (if i am angry).
Being angry is my biggest weakness, and i get ticked off by slightest of things and i know how i try to bring my steam off..because there have been instances when i have shown my anger and frustration and have driven even my friends away and my family thinking im a brat who just cant think before acting.
Im conflicted..as to when to be myself? I know my anger has created big problems so i always try to blow my steam off so i dont resent afterwards about hurting someone else. But if someone like me, is angry, should we "be" ourselves? Then we get the rules of how to behave and how to deep breath excercise..so then in this world..in order to be accepted in all walks of life..you should be yourself, but just the right amount, not completely or people no matter how close they are will leave you?

I think that you can be yourself, while managing the things that may be considered unpleasant to others. I think that you should work on figuring out where the anger comes from and learn to manage it. Everything else you described seems like you are a well rounded likable individual. You just need to learn how to manage the unpleasants.

Thats exactly what i mean to ask..hiding my bad qaulities such as my anger or jealousy wouldnt that be drawing a wrong picture of me in someones mind? And if thats not the case then how can i manage my anger? Im a competitive individual i get anxious and jealous very often too how can i manage that?