While doing meditation, I am feeling intense sensations on my forehead and after sometime my whole will start shaking and my hands become rigid. Why are these things happening?Whether i am doing the meditation in the wrong way?
It maybe several things.But here's something to investigate.You may or may not have this problem.If your doing anapanasati meditation with the aim of developing tranquillity your body should be relaxed.Having intense emotions on the forehead,body shaking,and rigidity could indicate excessive effort,you may be paying too much attention on the breath in a stressful way.Notice if your breathing heavily as well.Try not control the breath.Loosen the grip.If possible repeat "calm,calm,or relax,relax,let go,let go" while breathing in and out.
Which meditation method you are doing? Whenever you do insight meditation, the most important thing, strong belief in your meditation master and meditation technique. Once one undergo some kind of strong experience either tolerable or not, then he/she must know these are the consequences of before-life experience or the experience in this very life before this practice. So please don't disappoint at what occurring. Please stick to the practice. Nothing is permanent. Strong belief and effort will lead you to another step.
Sounds like you're doing fine. What you are experiencing are just the first signs of samadhi. As your mind begins to collect and your body relaxes, there is a tendency to shake a bit in chronically tight muscle groups. You've probably always been tight in your hands; you just never noticed before! ;-) The feeling on your forehead is no big deal. It might even travel to different places. You might even feel like your head is getting inflated like a balloon, that your body is twisting, that your head is vanishing, etc. etc. etc. All of these kinds of things are very common. The first signs of samadhi manifest differently from person to person. You'll get used to it.
Whether i am doing the meditation in the wrong way?
This is right nor wrong these experiences come and go.
Why are these things happening?
When you meditate you stop creating new fabrications. Many of these experiences are your past fabrications manifesting themselves. More details see: That "Electric Feel" body sensation during meditation
What you have to do is continue equanimously without giving importance or thinking and pondering about the experience.