Am I Really Unable To Do It?

AM I REALLY UNABLE TO DO IT? 

When I feel that I am unable to do it, is it due to my lack of ability? Am I afraid of the outcome and hence do not have courage to progress or is it that I do not want to do it at all?

我是真的不行吗？

我之所以会觉得自己不行, 是真的因为我能力不足吗？ 还是因为害怕结果而不敢向前？ 又或者是自己根本不想做？。。。