I'm just gonna say that buying a bunch of textbooks and expecting them to improve my Japanese never worked for me. The last textbook I bought cost quite a bit of money and I spent maybe an hour or two with it before I realized it was the same old thing and wasn't even touching the surface of the everyday phases my Japanese friends were using.
I had a couple of other textbooks that I used in some of my courses, but they were more geared towards reading comprehension for young Japanese. Needless to say that was a pain in the A to try to understand and I just barely got by... comparing those books with the textbooks I had used up till them was a laughable experience. It seemed like there was so much grammar and so many patterns that weren't in my other textbooks.
I haven't looked back after ditching textbooks... in my opinion, though, yuo need to find a way to study that really works for you (as in a type of studying that produces actual results... IE being able to communicate with natives). Being at a college with study abroad students from Japan gives you a great advantage. I say this because they obviously will know some English and you are obviously studying Japanese... this creates a situation in which something called interlanguage is used. I think that was the key for me in being able to speak Japanese. Intelanguage was in my experience the stepping stone to being able to speak Japanese. I can go on for hours on how I've realized it worked in my experience, but I'll save it for anyone who's interested.
Here is the wikipedia article:
Interlanguage - Wikipedia, the free encyclopedia
My personal definition of interlanguage slightly differs from what is provided on wikipedia. When I say interlanguage, I am most certainly talking about what is on there, but I am also talking about using a mixture (almost like a pidgeon language) of Japanese and English. For instance, you might be using the Japanese grammar that you know, but you might not know all the words, so you'll say the Englsh words that you don't know in Japanese in hopes to keep the flow of the conversation going. It's very complicated to explain, but in practice it's quite simple and effective. For an example of this kind of "interlanguage", check out the M-flo song entitled "Miss You" (they have other songs like this as well). The PV should be on Youtube if you wanna check it out. I've talked to Japanese people, and they don't really udnerstand the lyrics in the song, I've talked to English speakers and they don't really understand the song. If the person is bilingual (or approximately bilingual), they usually understand it. Just for the record, I doubt they were thinking of linguistics when writing that song. However, their accents, intonation, and word stress is really phenomenal in both languages (and their usage of slang is really incredible).