From a lack of confidence or a lack of drive - but fear not! You have friends and fans here who are anxiously awaiting more of your writing. To paraphrase Andrew Jackson, do not take counsel of your fears, nor your doubts.

You should be writing what you want, and doing it because you want to. Not because someone else desires it or approves of you. If it pleases you, then worry not about whether or not another may feel it is inferior. There are always people willing to detract from anything we do. But just the same, there are plenty of others here who look forward to reading your work and will always support you.