well, you still have time to improve
it. You
could read english books ( i recommend ''the island'', it isn't that difficult and it has
an interesting vocabulary, and if you want something more difficult you can
go read some book by dan brown or stephen king. A book I love and i've read
in the english version is ''confessions of a shopaholic'' but i dont think you would be a fan

) or english newspapers such as new york times (do not buy financial times they are godawful and bo-ri-ng) and, of course, magazines. You could also watch movies without the subs or with english subs, it will really help you to improve your skills, and of course
try chatting. Chatting really helped me, lol, see how I say "u" for "you"? and I also met people from all over the world (i love the japanese!)
Just don't throw up!!