Are you doing the following things in order to prepare and practise for the IELTS listening test?
- working through as many of the tests in the official Cambridge IELTS books as possible
- doing the listening test samples on the official IELTS website here
- analysing any mistakes that you make when doing the above tests
- listening to difficult parts of each test several times, until you hear and understand all of the correct answers
- checking the written transcripts (at the back of the Cambridge books) carefully for any questions that you found difficult
- noting new words and any spellings that you got wrong
- listening to as much English as possible to improve your ear (not just IELTS tests, but news reports, documentaries, talks, presentations, interviews, films, TV programmes etc. that you find on the Internet)
If you're doing all of these things, keep going! You might not notice it, but your listening will be improving gradually.