Physics & Maths tutor, JEE Main and Advanced Expert, IIT Delhi Student, Olympiad Specialist
The key to speed lies in problem solving. If your concepts are clear, that is a big plus because I can personally guarantee that you will be over the speed issue in no time
What you need to do to increase your speed is to just start solving questions. Solve multiple questions, of the same type, with a simple change of figures and values or anyhting of that sort. Solve plenty of questions, and don't worry about the time you take. Slowly, and successively, the time that you take per question will decrease, increasing your speed manifold.
Physics Tutor, IIT Student, IMO International Rank - 560
In order to increase your speed, you need to practice a lot. You must practice same question about 3-4 times in a time frame so that you can get to know the feeling of the exam.
You must prepare a schedule for you practice. For example, you solve all questions of a chapter. You need not have time limit for your first attempt. Then look at the solutions and learn new tricks in the solutions. After 3-4 days, do the same questions (ignore very simple questions) in a time frame like 30 questions in one hour. Again, look at the mistake you did in the second attempt and after 3-4 days, do the same questions again in more stringent time frame like 30 questions in 40 min. This will make you used to the exam pressure and how fast you can do in the exams.