It happens many a times that with so many options available one tends to get a bit confused.
When you say that you are interested in the stream (commerce) and also in subjects like economics and are still not able to score well in it, you need to delve deeper and try to find out what is it that is creating an issue. Economics is a theoretical subject,nevertheless it can be applied too. Try looking at the application bit of it and you will be able to get the concepts well.
Even your parents are equally worried about you and your scores and that how they are trying to recommend all the possible things that will help you.
In your case its advisable that you log on to http://www.youngbuzz.com/career-assessment/role-assessment-career-counselling
The test will help you know your interests (likes/dislikes),aptitudes(your potentials) and your personality (your work values). After taking the test you will get your profile with the career recommendations by the YoungBuzz career counselors. You can in case of any doubts contact the cousnelors and also have a one-on-one with them for further clarifications.
This will surely help you.
Nevertheless, like you said you would want to know the scope of economics, log on to http://www.youngbuzz.com/careers/careerdetail/career-economist You can also read up on fashion designing and other career options
available in commerce.
Kindly revert for further queries.