I'm coughing real blood and I've got chest pain. No fever, but constant cough (big smoker). Will amoxicillin take care of it?

NO. You need a bronchoscopy and cat scan thorax. Coughing up blood or hemoptysis is one of the possible presenting symptoms for lung cancer. You need to see a pulmonologist as soon as possible.
Need Eval Today... You need to be evaluated by your doctor asap! if you are having any shortness of breath or if this worsens, go to the er. This may be acute bronchitis that will respond to antibiotics but this could also be due to a malignancy, especially in a smoker. You need to quit smoking immediately as well and your doctor can help with this, too, please see a doctor today! good luck!