How can I stop a severe toothache?

The best thing to do is see you dentist. I know you can't get there now so you will have to resort to another alternative. I would start with 2 tylenol every 4 hours, I would also rotate that with ibuprofen. You can take up to 800 milligrams of ibuprofen every 8 hours. Some other tips: gargle with warm salt water, press a cold compress against your face. I have found the cold compress works the best. I get comfy and lay on it. Most likely even after you see the dentist you will have to keep this regiment up. It seems like you are going to need a root canal. The dentist will give you antibiotics to get rid of the infection but that won't stop the pain. I am going through the exact same thing now. I went to the dentist yesterday and got antibiotics and I have to come back in a week for a root canal. Unfortunately I still have to cope with the pain until then. I hope this helps you out.