I’m going to dissent a little from the consensus in this thread. I am a huge believer in the value of foreign language education, and my own foreign language studies have been an important part of my life.
That said, I think: (a) Most of the moral/educational/civic goals of foreign language study have already been met when a child whose home language is other than English learns English while maintaining fluency in his home language. (b) The on-the-ground quality of foreign language classes in most American high schools is below abysmal. In many cases there is absolutely no value, in terms of the lofty goals supporting foreign language studies, in having a student start a new language and take a year or two or even three of high school classes in it. © There are many elite universities that are happy to accept proof of fluency in a language other than English by test as satisfying the university’s foreign language study requirements, either pre-admission or as a degree requirement, even when the language is the student’s native tongue and English his second language. I don’t know if that’s true of the UCs, though.
As a caveat, there are plenty of native English speakers whose command of English grammar, vocabulary, and syntax, not to mention reading ability, is awful because they have never had effective education in those areas. The same is true of lots of native or near-native speakers of non-English languages. It doesn’t seem to be the case with the OP, but many native speakers would struggle with some aspects of a college-level fluency test.