I'm guessing that you've copied and pasted stylized text from MS Word directly into the design view of DW. If that's the case, then yes, you're going to have a tough time organizing your code and keeping things straight.
If I'm guessing correctly what you should do is "clean" your text by pasting text into a text read first and then into the design view of DW. Apply any styles via css yourself after the text has been pasted. Of course, the ideal option is to paste text into the code view of DW and create your css to arrive upon the desired styles.