well the dream dictionary says this is what anaconda means:
Anaconda
To see an anaconda in your dream symbolizes your creativity and potential. This snakes also calls attention to your sexuality and your need to be more in tune with your own sexuality.

so the rest of the dream you can take literally. you are afraid of these things in your life. your creative or sexual impulses. you are fighting them and running away from them, killing them. you need to ask yourself why your fear them? why are you trying to stifle them? and the dream will probably go away.