Nice progress so far! Really great work.
I do think it's likely that you will need more than 3 weeks - 80 points is a substantial improvement and most people would need more time. And studying for 20 days straight is just likely to burn you out by the time of the test and then your score might even drop - you can't really cram for this kind of test. Do you have the flexibility to postpone your test?
Have you been taking your practice tests under official conditions, including essays, length of breaks, etc? If not, then it's possible that your practice test scores are a bit inflated (if you are giving yourself advantages that you wouldn't have on the real test). If that's the case, then it will likely take even longer to reach your goal, so I want to make sure that we're accounting for that.
Use the below article to analyze your most recent MGMAT CAT:
http://www.manhattangmat.com/blog/index ... ice-tests/Then come back here and tell us your analysis (note: NOT just the raw data - your actual analysis of the data!).
If you discover that you have timing problems, read this and start doing what it says ASAP:
http://www.manhattangmat.com/blog/index ... anagement/(Note: it typically takes about 3 to 6 weeks to fix timing problems - closer to 6+ weeks if the timing problems are significant.)