I fail in maths. Please help me. What to do ?

You will need precise help and very good reference books. You also need to be ready to refer back the earlier class maths book, if required.Try to understand the concepts well with practical applications. That would generate a great interest in you and you will start loving the subject and solving problems. Please clear your concepts from beginning. You will never fail if you start right from the scratch.

See there is only one way to keep Maths in your control. You need to understand the concepts properly and little practice will do wonders. 

Everyone says you can command over Mathematics by practice. But I feel without understanding the concepts, if you keep on practicing it won't give you better results.

I am a teaching Maths since 5 years and as per my experience I say my students that there are uncountable number of questions from each topic. It is quite impossible to practice all of them. But if your concept and understanding about a particular chapter is concrete, you can attempt any question. What i want to say is suppose you practised 10 types of sum in a particular chapter but in exam 11th type of question came. So you will be scared to attempt that question. But, if your concept is clear, you will be able to solve that question very easily. 

So, my suggestion for anyone scared of Maths, you just need to make your base strong with the help of concept, then only you will be able to build your own building. If base is weak, the building obviously going to fall sooner or later.

If your concept is strong, a little practice can do wonders.