I fell on friday nite and hit the back of my head pretty hard did not lose consciousness but my head where i hit it really is sore to the touch.. and can't sleep on that part of my head. how long will this last should i see a doctor. thank you?

You probably have a blood collection/hematoma at the site of trauma and it will resolve. It may take a few weeks to recover. If it is getting better, even slowly, you may watch and wait. If your symptoms worsen, it would be prudent to see a doctor.

A localized hematoma over scalp will likely resolve over several days, and would not require urgent care. But if headaches, dizziness, imbalance, visual blurring, double vision, nausea and vomiting, confusion occurring, a doctor's examination would be necessary.