Word numbered list indent second line

I have created my own multi-level automatic numbering lists, which are working great. However, as the numbering indents progress, the space for text shrinks as well, until my paragraphs take up only half the page. How do I make Word send the second line of text back to the left margin, rather than staying under the new number/letter?

In other words, even though subsequent numbers/letters in a numbered list will continue moving to the right, like this:

1.
2.
3.
[_indent_] 3.1
[_indent_] 3.2
[_indent_] 3.3
[_indent__indent] 3.3.1
[_indent__indent] 3.3.2
[_indent__indent] 3.3.3

I want the second line of any text entered under any of the numbers/letters to begin all the way back at the left margin, rather than beginning under the letter/number.

Any suggestions?

Thanks!