Let's get one thing clear right now, shall we? There is no Idea Dump, no Story Central, no Island of the Buried Bestsellers; good story ideas seem to come quite literally from nowhere, sailing at you right out of the empty sky: two previously unrelated ideas come together and make something new under the sun. Your job isn't to find these ideas but to recognize them when they show up.
Almost everyone can remember losing his or her virginity, and most writers can remember the first book he/she put down thinking: I can do better than this. Hell, I am doing better than this! What could be more encouraging to the struggling writer than to realize his/her work is unquestionably better than that of someone who actually got paid for his/her stuff?
I have spent a good many years since--too many, I think--being ashamed about what I write. I think I was forty before I realized that almost every writer of fiction or poetry who has ever published a line has been accused by someone of wasting his or her God-given talent. If you write (or paint or dance or sculpt or sing, I suppose), someone will try to make you feel lousy about it, that's all.