I need to know how do you get rid of the pain after a root canal is half way through with a temporary filling?

Yes and No: If you had your mouth open for quite a while your jaw muscle could be sore. Your gum may be irritated from the clamp. The disinfectant used to clean the root canal can irritate too. If you don't feel better after 2 days call your doctor (or sooner if you're concerned). Meanwhile, take whatever you dentist prescribed or Ibuprofen 600mg every 6 hours. You should not be in extreme pain, however.

Toothache: How long ago did you have the first half of the root canal completed? If you are experiencing pain, then I would call your dentist and let them know. They might want to get you back in. They might be able to get your some pain meds. You might even need some antibiotics. Call you dentist and they will help you out. That's our job.