sir i m a class 12 student amd a jee aspirant.i find physics really difficult.i m not able to do many qustions in hc verma. and then i start doubting my preparation . pls tell me some measure so that i become confident in phy

dear student 
donot get nervous , always start from the beginners level , then go to difficult ques , if you cannot then go with solution , no issue in that . 
for phy take the following meausre 
1- make sure u knows about all units and its interconversion  
2- make fast calculation and increase the baility to draw diagrams in phy , 
3- you should be well versed with trigonometry concept and graphs . 
4- always learn from your mistake while you are going through examples . 
5- spend time in numericals , not only theory . 
6- solve previous year paper . 
HOPE IT HELPS 
REGARDS 
kindly approve