Hi nikosgan,
Assuming that you took your practice CATs in a realistic fashion that matches-up with what you will face when you take the Official GMAT, you will likely need at least another 2-3 months of consistent, guided study to get to the point that you can consistently score 650+ and you will have to make significant improvements to how you handle BOTH the Quant and Verbal sections. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level.
I want to reiterate that shifting to study for the IELTS at this point would likely be a smart choice (since the skills that you will develop for the IELTS should help you to improve in ALL areas of the GMAT, whereas only some of what you will learn for the GMAT will help you on the IELTS).
To be efficient with the many months of upcoming study time that you will face, you would likely find it beneficial to invest in an IELTS and/or GMAT Course of some type (either Guided Self-Study or instructor-led). While I don't have any suggestions when it comes to an IELTS Course, most GMAT Companies offer some type of free materials (practice problems, Trial Accounts, videos, etc.) that you can use to 'test out' a product before you buy it. We have a variety of those resources at our website (
www.empowergmat.com). I suggest that you take advantage of all of the available options for both Tests, then choose the ones that best match your personality, timeline and budget.
GMAT assassins aren't born, they're made,
Rich