Manpreet01,
Besides what the numerical score says (seems like a huge drop in Verbal in comparison to what you say you normally get), how did you feel?
Did you feel as comfortable as you normally do? Or do you think the exam anxieties got to you? Did you finish the verbal portion--or did you have to rush and randomly guess?
You shouldn't be asking about how to increase your quant score----rather, the focus needs to be on your verbal. Q42 an V19 is too much of an imbalance. Adcom at any school wouldn't particularly like that.
It's also important to do your practice exams in as realistic of a setting as possible. For example, if your real exam is in the morning--make sure you do a practice exam beginning early in the morning to get yourself in the same psychological state. If you work during the weekdays, then budget time on the weekends to do those practice exams.
I'd also recommend reading this article on psychology and timing strategies:
https://www.gmatpill.com/about/studying- ... trategies/ Hope that helps!