In my opinion, learning English is a long process that needs your patience and hard-working. There was a saying "Rome could not be built in one day". It is also the same in learnign a language.
You want to improve your English, spend at least 1 or 2 ours per day for self-studying. Do not spend 7 hours for one day of a week.
For listening, listen to music, watching film is one of the way. Moreover, what you listen in class is acamedic English, not comunication language. You should buy a Toefl CD, or CD of "Listen and Hear"(this kind of book has 3 level ) to listen.Listen and Hear is a very easy book to listen for beginer. Obviously, it is not as interesting as music or film, but this is what you need to improve your listening skill.
For reading, when you read the paragraph, you should focus on the first two sentences and the last sentence of the paragraph. You should know the general , or the main point first before coming to the detail. Another way, buy some advanture or retail book to read for fun. It not only help you to improve you reading skill, but also provide you good relaxing time.
For writing, do not try to write a long sentence. Do not try to impress your instructor with a long or complex sentece. Make it simple. When you read the book or article, pay attention to the way that the writers use and try to imitate them. Do not copy their words, I said follow their way of writing, it is not easy, but when you try, you will improve.
For grammar, when you can write well, grammar is no more a problem.
It is all my experience. If there is anything wrong, please let me know as soon as possible.
Khang