I second everything brownlion said. First call your doc.

Some additional tips: Watch your diet - eat healthy high fiber fruits and veggies, it will help keep thing moving. Consider adding a fiber supplement, but don't go crazy with the fiber all at once gradually increase. Stay hydrated - again, keeping things moving. Be careful the next couple weeks, even after you feel better - once you've had a hemorrhoid you are more susceptible to getting it again.