Wisdom tooth growing/pain, gum covering half of it.?

i am 18, and all my wisdom teeth have came through and their fully grown exsept for my lower left 1, sence yestherday i've been in pain with it. my gum is covering half of the tooth. (not a flap) it's like it's grown in to my gum. and i'm in pain! when i swallow i get a shock of pain in my lower left of my jaw, the tooth has been there awhile with the gum covering half of it, i thought it was ok. till yestherday morning when i woke up to really bad pain! is there any sort of pain relif i can buy/make. that will stop the pain till i go dentist? or if any1 knows if this is normal. maybe it hasnt fully grown yet?