First, get the dosage (750) of acetaminophen down to 325 or no higher than 500. The amount of acetaminophen you is taking is eating up your liver. I am surprised your doctor has you on such a high dosage of acetaminophen. Then talk to your doctor about the cause of pain. The vicodin is just masking the pain and not solving anything.
You will constantly need more vicodin because your body will adapt to the drug and you will constantly need higher dosages. I know, I have been going through the same thing for the past 11 years. My dosage is 325-5 and I am up to taking two each occurrence of pain. Good luck.