Firstly, there is no such thing as an easy subject in VCE. A lot of work would have been loaded onto you, even from the so-called "easy subjects." I am not really sure if you can do English Language outside of school, as that depends on the policy of the school. You will need to check with your school first because, in the end, you will be doing your final exam at school. Is it too late? Well have you signed the VCAA form that detailed all of your subjects? If you have, it is likely to be too late as you may be fined of you change subjects.(I am not sure but this is what I heard).
And for English, your teacher should be happy to help, but bear in mind that s/he may be busy with 20 or so students asking for help. Also, you could get a tutor, which would also help you.