Holy Geesh, scar!!
1. One who believes in the existence of a god or gods
You are not a theist.
Therefore you don't believe in the existence of a god or gods.
You said "I'm not a theist."
A theist believes....
An atheist (or non-theist) doesn't believe..........
You're finally getting it.
An atheist does not have the belief of the theist there are deities.