Let me start off by saying that I am not a doctor of any kind. So everything I say has been gathered from my experiences or things that I have read. But I felt compelled to answer you because you seem so upset.
I think that you are doing exactly what you should be doing, which is going to a doctor who specializes in internal and digestive problems. More than likely they will want to do tests on you and they will be able to check for reflux, cancers, h. pylori and stuff of that nature. I do know that the acid in the throat feeling and the heartburn are both symptoms of GERD or LPR.
I do not know much about the blood. I do have a friend who was having small amounts of blood in her stools. The doctor determined that she had polyps and they were removed. They were non cancerous and now she is fine. She just needs to get regular checkups from her Gastro specialist. I think that you can also have polyps in your upper digestive tract, so maybe that is responsible for the blood.
As far as what you should be eating. If you have GERD or LPR you should avoid foods that are acidic (like tomatoes and orange juice), fatty, and spicy. You should also avoid coffee (regular and decaf), tea, carbonated beverages, and onions. I may be leaving stuff out, if you search the boards you can find a list of the foods that you should avoid. They also say that you should elevate the head of your bed by 4-6" and to not eat after 7pm.
I hope that this helps.