www.examenglish.com/IELTS is free and may be helpful. They have tests you can practice with. Just google ielts free and lots of people will help. If you try a test and need a marker, send it to me. I spend so much time marking I won't even notice one more student.

I recommend English text books. You could use multiple books with this amount of time. They will give the same information in different ways. Could you visit with a friend that has taken the test? Do so. Some tests have on line practice examples that you may need to pay for. These are handy.