Hey,

Okay considering your situation, i would say stick to bsc. But you should lnow that bsc is more theoretical and lab practicals while btech is more about actual industrial application. Other than that yes, anywhere you go math will chase you, especially in cse, matrices and vectors might be the foundations. 

And maybe you may get a job as a researcher, but honestly if your math is that bad, reconsider taking cse. Dont do it just for the money after the course, because you may not be able to finish it in the first place.