in immense back pain after i sneezed once.

So, i am 25 and i am delivery man for construction company which involves heavy lifting studs and drywalls. i hurt my back last week by lifting the studs using bad posture ( atleast thats what i think ).

i took a week off work and was feeling little better finallly but as this saturday, i woke up happily ( not feeling any back pain ) , i had a sneeze and i was standing when i sneeze my whole back got cramped and locked like i got hit by a bazooka.

i went straight to my bed because i couldn't even stand at that point but now after 2 hours i can do some basic standing but whenever i lift my arms or bend my back a little bit , i feel the pain and its not going away.

should i just quit the job at this point or i should just take some medicines ? i haven't taken any medicines till yet but now i definitely needs them.

i never thought a sneeze will brake me down this badly, like i am already feeling like a old man at 25. just type it , yes i am UNC. i feels like i lost my freedom to move freely :(