You don't need a great business idea
If you overhear entrepreneurs discussing new business ideas at any random tech meet-up, you will notice that some are obsessed with finding the "great" idea. The fact is, however, that there is a surplus of good ideas, and there are many great ideas, freely available for anyone to grab and execute on.
The problems or success you may experience in trying to build a sustainable and profitable business can seldomly be traced back to the quality of the idea. Instead, your success will be dependent on other factors, such as marketing/positioning, product quality and price, your persistence and determination, etc.
Your ability to be creative, and deal with obstacles and lack of immediate gratification, are better indicators for your future success than the greatness of your business ideas.