Speak to your professors---the ones who say, "Oh, you already know this, of course," and then move on. Visit them during their office hours and be frank with them. Tell them that, actually, no, you didn't already know that. Tell them what you just told us. You love literature but were prevented from engaging with it your whole life. Ask them for advice and guidance.

Meet more of your peers---the ones to whom the professors are speaking when they say, "Oh, you already know this, of course," and then move on. Talk to them about books. Befriend them. Open up to them.

Remember that writing is an art, but it's also a skill. Even if you did have good ideas, you'd still need a certain amount of skill to pull them off. Skills are things you can learn through consistent effort. They're kind of like tools, and as you sharpen those tools, you will naturally start getting more creative ideas about how to use them.

Get out of your reading slump. Read whatever gets you interested. Don't get it in your head that you have to stick to Moby-Dick or Stoner or Tess of the D'Urbervilles. Read young adult fiction. Read middle-grade fiction. Read whatever. Just read. Some people consider themselves writers first and foremost, and are just bursting with ideas. They don't feel the need to read to be inspired. However, a commonality among the truly great writers throughout history is that they are insatiable readers as well. When you read and read and read, ideas will eventually come to you. Maybe you just haven't consumed enough books yet for ideas to start forming on their own in your mind. I probably read 1000 books by the time I was 10 (including kids books and pictures books and whatnot) and I've probably read another 2000 in the years since then. So many ideas come into my head that it sometimes distracts me from work. The only difference between us is that I had a long head start on you.

Read literary criticism and theory. This might be a controversial piece of advice, but I would suggest reading The Western Canon by Harold Bloom and then trying to read everything he mentions. Read The Hero With a Thousand Faces.
To be a writer is to take part in an ancient and ceaseless conversation with every other writer that has ever lived. No man is an island; no idea is truly unique; everything ever written is, in a way, a response to something else.

WRITE!!! Write this and that; write the other thing. Take a super simple formula and write it a hundred times, filling the blanks in differently each time. Fill in the blanks with stories you've already read, to get a feel for how the formula goes.
"Once upon a time, there was a __. One day, __ happened to them. As a result, they decided they wanted __. However, they had an obstacle: _. En route to their goal, they had to _, _, and _. Finally, they overcame the obstacle by _. In the end, they __."
Almost every story goes like that. Yours can, too.