I'll bet you have improved some, you just may not notice it. You are doing the first and biggest thing that will help you to improve you English: you are in an English speaking country. Here are some other suggestions, just in case you aren't already doing these things:
1) Hang out with the British, find situations where you can practice your English constantly, maybe even look for a volunteer opportunity
2) Take a class, a small one, or preferably, find a one-on-one tutor (some organizations have volunteers who will help you to practice your conversation skills for free)
3) Watch English-speaking TV, listen to the radio, and watch English-speaking films
4) If youíre trying to improve your writing skills, take a class or find a tutor, and write something everyday; keep a journal, what you write is not important, just write, you are trying to train your mind to think in English
Essentially, you have to inundate yourself with the language. And you have to be brave and not worry about making mistakes. Just speak as much as you can. Write as much as you can. And donít give up.
Teaching ESL to Adults