why do I hit in my dream?

Although I am not a dream interpreter, I found a site that defines what your dreams could possibly mean. They do have a disclaimer that it is for entertainment purposes only, but this makes sense:

Hit / Hitting
If you dream of hitting something or someone, this symbolizes unexpressed anger and aggression. You tend to keep your negative feelings inside instead of expressing them in a healthy way.

On a more positive note, I also found this: Hitting or being hit in a dream both symbolize expressions of love or fortune. If you hit someone in a dream, it shows that you care for that person. Especially it you’re hitting an opposite sex, there might be a possibility that you will fall in love with him or her nearly. Also, if you get hit by someone, it indicates that an unexpected fortune will fall on you. If that ‘someone’ is an opposite sex, you might be confessed love by him or her.

Do any of these meanings make sense to you?

http://www.smartgirl.org/dreamdictionary.html#h
http://dreamfortunetelling.com/dream-dictionary/h/hitting/