You don't mention your goal score, but I'm guessing that it's much higher than your practice test scores (because you describe yourself as very discouraged).
So I'll guess that you want something like a 700? If so, two weeks is not enough time - you're going to have to postpone your test. Whatever you're scoring right now is about what you should expect to score on the real test in 1 to 2 weeks.
This assumes that you took those practice tests under 100% official conditions, including essay and IR. Did you? If not, then your practice scores could be artificially inflated.
So, yes, you do need to make some changes in how you're studying, because you're not getting the level of improvement that you would like.
First, don't take any more tests. That's now how you get better :)
Read this:
https://www.manhattangmat.com/blog/inde ... lly-tests/Next, read this:
http://www.manhattangmat.com/blog/index ... -the-gmat/Follow what it says, starting with analyzing your most recent practice CATs:
http://www.manhattangmat.com/blog/index ... ice-tests/Also read this:
http://www.manhattangmat.com/blog/index ... -the-gmat/Then come back here and tell us the results of your analysis and
what you think you should do based on that analysis. We'll tell you whether we agree and advise you further. (Note: do share an analysis with us, not just the raw data. Part of getting better is developing your ability to analyze your results - figure out what they mean and what you think you should do about them!)
Make sure to include your goal score as well as your Q and V sub-scores. We need to have an idea of where you are and where you'd like to be.