Hi Shaharyar,
Please click here to review my analysis of your serve. The lessons and drills recommended to review are:
https://members.tennisevolution.com/topics/trophy-position-elbow-the-enemy/
https://members.tennisevolution.com/topics/pop-the-ball-up-drill/
https://members.tennisevolution.com/topics/nose-on-the-fence-drill/
Best,
Herman Krackow,
Head Coach