How to deal with constant pressure given by advisor
Every PhD student suffers mental trauma. You say your advisor "scolds" and "taunts" you. I think of scolding and taunting as personal attacks, and hence unacceptable. That said, your English makes me unsure if he is attacking you or your work. Attacking someones work is a common occurrence in academia. We tend to get one sentence notifications about our successes and pages and pages of feedback about our failures. Even the best researchers fail more often then they succeed. The key thing to remember is that, in general, it is not personal. You need to identify if your advisor is attacking you or your work.

You say your advisor "is not impressed with my good academic record and my hard work". Successful academics tend not to be impressed by academic records and hard work since it is par for the course. This doesn't mean they do not respect you. The best way to find out what your advisor thinks about you is to ask. Ask what you are doing well and what you can work on. Also say that you are feeling unsure of yourself and looking for reassurance. Some advisors will give you reassurance and a shoulder to cry on, others will simply tell you that you are not failing. Not failing is another word for a major success.