Infinite Quarrel

I've come to realize that in my lifetime, I've spent most of my hours fighting, arguing, and disagreeing. The concept of peace and truce has yet to dawn on me. And no matter how hard I try to stop, well, that's a whole 'nother fight in itself.
But this fight is not the typical fight. You see, my opponent knows me well - better than anyone else in this world. It knows what I'm thinking, what I'm feeling. Using my thoughts, it manipulates them and sends me into all sorts of confusion and frustration. It takes me and throws unto the ground with force so strong that I fall six feet under. When I climb out, it pulls me by the hair and throws me into the never ending forest before taunting me with insults that hurt so bad my ears begin to bleed and I start to believe they are true. So I kick it in the center and punch its face so hard, the blood has no choice but to clot itself in the socket. I yell at it to leave me alone, but my opponent is persistent. It swiftly kicks me by the ankle and I fall. I feel its grip on my ankles as it drags me where it wants me to be.
The looking glass is covered in dust and residue, but I see my opponent. Eyes a dark brown, hair the darkest black, and lips set like stone. Dark circles consume the eyes as it pierces through mine. Our movements are one in the same. As I lift up my hand to touch the cold surface, so does she. We blink the same blink, breathe the same air, and our heart beats the same pace.
But we are different. Our thoughts are different. She wants to be free, be selfish, be completely honest, be careless.
I call her monster, but she smirks and snickers. Then she stares at me hard and says,
"You say I'm a monster. Well then, what are you?"