I bit my tongue really hard on accident and now it won't stop bleeding and i don't know what to do?

First, pressure.: Use some gauze to get some traction and really apply continuous pressure to the wound with your fingers. Try to hold as long as you can, 20-30 min, with a minimum of checking. The tongue is rich in blood vessels and can bleed quite a bit. It should stop with pressure. Repair of tongue lacerations is controversial, and limited to very large, deep cuts. If it does not stop, then seek evaluation.