I seem to have an always stuffy nose. Please help!

My mom thinks blowing my nose is the only way to do anything about it. I keep telling her it doesn’t do anything! All I blow is air. But there seems to be a buildup of some kid of hard stuff in there that gets so bad that I have no choice but to go in the bathroom and pick (yech, I know). Today when I did this, I got a nosebleed. So what should I do? What is this that’s happening?