Hi, my name is Lucas, I've been writing since age 11 and I am now working towards my first full length novel, but that is where my problem comes in. For the past 5 months or so I've been dealing with extreme writers block and it is tearing me apart at the seams so to speak. I know that I want the story to be a post apocalyptic dystopian sort of thing but I keep changing the plot because I don't like what I have, or changing the conflict because it resembles too closely to other stories. I need some help. Badly.
What you're going through is a perfectly normal part of the creative process that most writers experience at one time or another. Some suggestions...
1. If you feel stressed out, relax. You're not on a deadline. You can take the time to weigh up different ideas for the story. Eventually it will all gel. Remind yourself what it is that got you excited about the story in the first place. Focus on that vision.
2. Don't worry if your story seems a little like others. There are few wholly original ideas. What matters is that you tell your story your way.
3. Try to separate your creative from your critical work. In other words, when you write or brainstorm, don't judge. Just have fun creating. Save the self-criticism for a different session when you go back and review what you have written. As John Cleese says, "Nothing will stop you being creative so effectively as the fear of making a mistake."
Sometimes the best thing to do is withhold all self-criticism until you have finished a first draft. Put the draft aside for a week or so. Then read what you have and make notes on what you would like to change in the second draft. It's much easier to revise a finished draft than to create something from scratch. And it's okay to write a first draft that you know isn't perfect and then fix it afterward.
Trying to criticize and revise while you are still writing a first draft is the easiest way to get confused. (And writer's block is usually the result of confusion.)
Finally, I am a big believer in outlines as a way to keep yourself on track. But sometimes you only discover the real story while writing. If the story changes in a good way during the writing process, you can always revise your outline for the second draft.
Best of luck.