Is this social anxiety?

whenever i'm at a social function...it's like there's this wall...sometimes at parties and stuff i can be "on" for like 15 minutes at the start...but then i fizzle out like instantly...and it's like i can't look at anyone in the face, laugh or smile. It's really weird and VERY uncomfortable. And usually when i leave the social function, i get in my car and i feel liberated...as if i was trapped during the party. Is this social anxiety? Should i get medication?