John,

Your problem statement really has more than one parts. First you need to show, using citations, that for native speakers, being required to use English in the classroom can be a source of anxiety.

Then you need to show the the specific aspect of this problem you are investigating has not been well-addressed in the literature. This may be because there have not been many studies using mathematics students as participants, or at least not in Pakistan. It may be some other aspect of the question that has not been addressed in as much detail as it should be.

This leads into your study goals and research questions, which you follow with a statement of why your study is significant.

Here is a manuscript outline that may help:

Conference Paper Research Study Manuscript Outline

Before beginning your problem,you should decide what do you what do you want to measure in your experiment or what are the goals that you want to reach. Problem statements such as; students levels in English impact on Math problems performance, or The difference between learners in English levels and its impact on Math performance. I mean that you can classify your class into tow groups to measure the English levels on Math problems.

If you want any other support I can help you.