Random nose bleeds repeatedly after blowing it?

No, it's not from blowing too hard. I can blow it gently and it still bleeds. The bleeding is nonstop, it could bleed for almost 3 minutes. Sometimes it comes out in chunks... I went to the doctor two years ago because of this, he told me I'd need surgery if it keeps up. But what's the problem? I get these terrible headaches; and even vertigo... This is really a pain in the rear, I refuse to get the surgery because I'm in DEP for the US Navy. HELP?!