How to change my personality?

I have a horrible personality. I struggle with showing any emotion except anger..I easily get mad and lash out at the people I love and say extremely stupid things I don't mean >.< Then I just can't stop being a prideful ***** even after I've hurt people..I could go on and on about how I can never make a person laugh, I'm way too pig-headed and stubborn to listen to anything people have to say..etc. So, enough about my personality, any tips/advice on how to change it to a more sweet, girlie personality? No rude comments please :/