I also have a ton of ideas, but find it hard to choose one to work on. I found that it's nearly impossible to think of a brilliant idea for a business. Instead I focus on ideas that I am passionate about and rely on potential customers to help be develop the idea.
For example, I am passionate about playing poker so I came up with a business idea that involved selling information to poker players. My idea was not very good at first, so I identified my target customers and did some interviews. Each time I talked to a poker player I refined the idea until it became a brilliant idea. Of course, in the end I was selling a completely different service than I originally envisioned.
I think you should focus on learning how to turn a mediocre idea into a brilliant idea, rather than trying to spontaneously invent a brilliant idea.
And choose something you are passionate about, otherwise you won't have the motivation to get you through the hard times.