But does believing that I have them imbibe those qualities in me?
Sometimes, yes, it actually does. Sometimes if you think you are incapable of compassion, you do not show compassion or try to as you believe you cannot (making it futile). Sometimes you think you are always angry, so you walk around angry all the time to prove yourself correct. Sometimes you believe you cannot love or cannot be loved, so you walk around rejecting everyone, including yourself.
However, were you to believe you can show compassion, you would try to show compassion and eventually succeed, thus giving compassion. However, if you were to say you were happy on occasion, you would find yourself happy some times rather than angry. However, if you believed you were capable of feeling love and being loved, you would find yourself willing to put your heart on the line for someone you've known for four years who may or may not like or love you back simply because you believe that you are finally worth the possibility of rejection and worth it to spit in rejection's face in order to prove to yourself you are capable of feeling love and being loved.
It is always a mind game. Always. You choose who you are. You choose what qualities you have and display, whether that be anger, depression and defeat, or rather joyfulness, strength, and love. You can choose to feel rejected by society, you can feel as if you have a legitimate reason to be angry at the world for what your father did (and you do), or you can choose to see that you are worth more than anger and depression, despite having all the right reasons to feel each and every downed emotion. It is in your mind, and you alone choose what you think and believe.