Forget about [i]"i think that my problem hunting skill is not enough... that's all... "[/i] - [b]this is not a problem, this is simply choosing a topic for your Thesis.
The problems come when you are assimilating the information for the Thesis, presenting it in an orderly and cogent fashion, then drawing your own conclusions from what you have discussed within it.
I suggest you approach your Tutor and discuss this matter with him. Doing so will NOT result in any de-merit.
I can say this with a degree of certainty (pun intended!) because in the Autumn of 1977, I was in a queue of 18 standing outside the Tutor's Office with exactly the same intention! :)