Have toothache been to dentist and told it's not an infection. Pain is so bad can hardly eat or drink and when I do manage to I'm sick. What 2 do?

2nd opinion. I agree a second opinion is indicated. Ask for referral to endodontist.
See an endodontist. Endodontists are dentists who specialize in saving teeth, and have at least 2-3 years of advanced training in root canals. They are experts at diagnosing and relieving tooth pain and use advanced equipment to treat patients efficiently and comfortably.
Second opinion. Are your wisdom teeth coming in? Did the dentist radiograph the area in question, or was it a quick clinical examination only? There are many variables, if you are not comfortable with the response, seek another consultation with a different dentist.
More info needed... Have you been treated, or do you need treatment? We know it is not an infection, but since you've been to the dentist why are you still in pain? Please revisit the dentist and have the situation re-evaluated.