I can't speak for English Literature, but I did English Language U1/2 in Year 11 and mainstream English U3/4 in Year 12.
I'm happy with the decision I made to switch as I found English Language to be a bit boring, I wasn't a fan of writing ACs and analytical essays. My cousin who is doing EL U3/4 currently said it was pretty much the same stuff from Year 11 but more metalanguage, more detail and more depth, mostly just building on the U1/2 content. One thing that I really liked about EL U1/2 was the fact that I found what you were writing was either right or wrong, it wasn't based on your teacher's interpretation like I found my work in English U3/4 was.
If you are passionate about both Literature and EL then I would say go for it for U1/2! You can always change your mind at the end of Year 11 and choose to pursue only one of the two, or you can continue with both. Or you can also always pick up English for Year 12 if you have a change of heart.
I hope this helped! Best of luck with your studies and let me know if you have any questions, (I'll pass on any English Language U3/4 questions to my cousin)