You mentioned you are good at English. Whether you study from CBSE or from BSEB, you'll have English as a core subject (unless the medium of education is not in English). It's time to re-evaluate if you like Science or lean more towards Arts/humanities. I'd suggest to go towards Arts from CBSE. CBSE is a recognized board and the marks are accepted everywhere. You can alternatively choose BSEB for the same. You can get admission into good universities in Arts/Humanities course based on your score, like Delhi University, Christ University, Madras University, Jadavpur University etc. Good luck and work hard.