Thank you for the elaboration. I have based my answer on one of your comments;
"...Lanka I have to say that, i experienced consciousness, but its like a temporary spark(for few seconds), it is not in a stable state.. in which i can get hold of it and continue in being in that state.. that is my problem.. and more often i encounter the situation i described above.. And if i feel frustrated because of this state..."
First of all, don't feel sorry or frustrated because you cannot stay in a certain state.
Instead understand, through insight meditation, that this is actually the impermanent nature of conditioned phenomena that you are experiencing. You cannot control anything as long as being in Samsara, i.e. the conditioned realm. Trying to control stuff is actually the source of your (and others) frustration.
All condition phenomena, whether mental or physical, follows a specific recipe/process. See drawing.
So when something comes into existence, it persists and then breaks up and falls apart. Even in the middle part of the process, i.e. the Presence-part the phenomena is already falling apart. It's already travelling towards its own disintegration. Nothing is stable. Everything is in a constant flux and no matter how hard one tries to hold onto the object, it will vanish as sand through ones fingers.
That is simply the nature of conditioned phenomena. One cannot really understand this through the process of thinking or intellectualization. Instead one has to practice insight meditation (Vipassana) and see with ones own eyes how phenomena arise, persist and disolves into nothingness. When the mind has seen that enough times it will begin to let go.
As the Buddha said; "Having known the world's impermanence, They (disciples) made an end to suffering1".
Trying to grasp at things creates attachment and as long as there is attachment, one cannot be free. Having something as your target might instead become a hindrance, depending on the intensity of the craving. The mind is like a little child or a dog, you have to teach it over and over in order to develop and purify it.
Lastly, don't be too hard on yourself. Think about it, we are all in the same boat, trying to become free from Samsara. We are just on different steps on the path. Being born human is extremely rare. Being lucky enough to come in contact with the Dhamma is even more rare. You are here now and that means countless of life times of performing wholesome and meritorious deeds, e.g. the practice of meditation.
Let me know if you have any questions to what I wrote and I will try to answer you. If you are interested in the technique I practice, I will be happy to share it with you.
1 Samyutta Nikaya: Sagathavagga: Devaputtasamyutta: Connected Discourses with Young Devas, Bodhi trans, p. 139.