Should I Major to become an english teacher?

I'm a non-native speaker.. My native language is spanish and I have been in the country for around 7 years.. My vocabulary is not too great yet and I rarely practice with anyone the language since everyone I know only speaks spanish.. When watching movies: I can follow about 80% of what's said.. Should I change my major to something else or keep it up? I just don't think it'll improve enough to the extent of being a good english/esl teacher in the future (about 7 years). I would go with Math but i'm terrible on that subject.. And I don't know what else I could be good at besides teaching..Thanks for any feedback.