First of all I should know you are in which class, and what kind of difficulties are you facing in physics. Accordingly I can suggest you that what you should do to get comfortable in doing physics. As such physics is a very concept based subject, so according to me you should be reading theory of any topic very thoroughly and try to understand really well. Once you have understood the theory try to solve numerical without unnecessary imaginations. Try and solve them by simply making equations for each statement. This method should definitely help you in overcoming your problem with physics.