Your nature is Peace and Happiness. Thoughts are the obstacles to realisation.
One’s meditation or concentration is meant to get rid of obstacles and not to gain the Self. Does anyone remain apart from the Self? No!
The true nature of the Self is declared to be Peace.
If the same peace is not found, the non-finding is only a thought which is alien to the Self.
One practises meditation only to get rid of these alien fancies. So, then, a thought must be quelled as soon as it rises.

Whenever a thought arises, do not be carried away by it.
You become aware of the body when you forget the Self.
But can you forget the Self? Being the Self how can you forget it?
There must be two selves for one to forget the other. It is absurd.
So the Self is not depressed; it is not imperfect: it is ever happy.
The contrary feeling is a mere thought which has actually no stamina in it.
Be rid of thoughts.
Why should one attempt meditation?
Being the Self one remains always realised, only be free from thoughts.
~Talks with Sri Ramana Maharshi, 462