How Can I Control My Dreams?

When I fall asleep almost all of the time I know that I am dreaming. I try to control them, but they seem to have a mind of their own and do exactly the opposite of what I WANT them to do.

Once I was dreaming that I was walking with my friends. I didn't recognize this road so I immediately knew I was dreaming. Suddenly the road split into a two separate streets. I wanted to go right and I willed it to happen, my feet started going in the right direction but as I was getting closer, my feet decided to take a little walk and went the opposite ways. I even remember in my dream saying, "STOP!" to my feet. I then thought it over and wondered to myself, "can I really control my dreams when even my own feet won't listen to me?"

The other night I realized I was dreaming because I was sitting with a bunch of people with fuzzy faces. I wanted to fly and I thought about flying. Thought light thoughts and even jumped. I didn't fly. Then when I calmed down and tried to relax and will it to happen, I fell through the pavement and landed in a pool of water.

I stopped trying hard and tried to calm myself and not force myself to control it. I started to lift but then I just realized I was shifting to another dream. It is like being stuck in a book and you know you are asleep but can't wake up and can't control what is happening. Once I had a nightmare and I yelled to myself, "WAKE UP OR CHANGE YOUR DREAM!" It didn't work.

Can anyone help me?