"You're an intelligent young person but you need better instruction in language."

I have been teaching myself. The books that I have now I got from half-priced-book stores, so I am not sure they are the best ones to peruse. I have a glossary of semiotics terms, some grammar books from the 1950s, a book "for writers" from 2001, some books of structuralism and post-structurialism--which I do not understand much, but can read that it deals with language some--, an old book (maybe 15 years) on language and speech and how the two are connected, and some grammar test-books. As you can see, the information I have gleaned is very incomplete and slipshod. Maybe my approach was smart, but my materials are sketchy. Hmm... How should I continue, then?