I need help on a thesis. It's on Winston, and how he has external and internal conflicts with himself over the Party.
You are pretty close to a strong thesis if you just invert your question a little bit. Think about what it is you want to prove with your essay.
If you are wanting to express that these external and internal conflict contribute to the overall message that Orwell shares with readers then state that.
Are you needing to cite literary devices for your essay?
In thinking about order, are you wanting to show that he goes from one type of conflict to the other? Do you need to show several of these components?
A strong thesis about literature will often list the title, author, and genre of the work if it isn't already stated previously in the intro.
Here is a sample thesis to consider, but it may differ from what you intend to prove:
Orwell uses the character Winston Smith in the novel 1984 to demonstrate internal conflict without relief will turn into external conflict.
I myself wouldn't write the paper to the above thesis, but it is a model for you to write your own thesis after. I would strongly consider using the words message, meaning, or purpose.