Hi AnuK2222.
It sounds as if your scoring below your practice test scores was to a large extent due to anxiety. So, there's no reason to be hard on yourself or lose confidence. You just have to prepare some more to make the final push to your target score and also do some things to address your test-day anxiety.
If you search online, you can find many articles and videos on reducing test-day anxiety.
Regarding how to prepare, I think one thing your perfomance on the test highlights is that you need to prepare for DI more similarly to how you prepared for Quant and Verbal. You should probably do not only easy and medium but also hard practice questions, untimed at first, and learn to achieve high accuracy in all DI question types.
In addition, you could identify areas of Quant and Verbal that you're still not strong in and work on those topics until you're achieving high accuracy in them as well.
Also, keep taking practice tests, and since 655 is your target score, shoot for a little higher on practice tests to give yourself confidence that you can achieve your target score on test day.
Between practice tests, review your performance on your last test to identify weaker areas and patterns of behavior that cause you to miss questions and strengthen the weaker areas and address the behavior patterns to score higher.