If you sit down with the pure intention to meditate, whatever happens next is none of your business.
Instead of trying to forceful take thoughts out of your mind, give your mind something better to play with. Something healthier.
Like love. Like pure divine love.
When I ask my mind to rest into stillness, it is astonishing how quickly it will turn (1) bored, (2) angry, (2) depressed, (4) anxious or (5) all of the above.
Like most humanoids, I am burdened with what the Buddhists call the "monkey mind" - the thoughts that swing from limb to limb, stopping only to scratch themselves, spit and howl. From the distant past to the unknowable future, my mind swings wildly through time, touching on dozens of ideas a minute, unharnessed and undisciplined. This in itself is not necessarily a problem; the problem is the emotional attachment that goes along with the thinking. Happy thoughts make me happy, but - whoop! - how quickly I swing again into obsessive worry, blowing the mood; and then it's the remembrance of an angry moment and I start to get hot and pissed off all over again; and then my mind decides it might be a good time to start feeling sorry for itself, and loneliness follows promptly. You are, after all, what you think. Your emotions are the slaves to your thoughts, and you are the slave to your emotions.