I was an atheist from birth until I became a Wiccan as an adult. However, I never felt a presence in my room or heard voices. Nor did I ever pray while I was an atheist, because I was an atheist at the time. I certainly did not pray to be forgiven for "sins," as I knew then, as I do now, that there are no sins, only choices, good and bad, which we are responsible for.
Your version of atheism seems so filled with belief in your god that it's completely alien to me... Are you sure you were an atheist-one who does not believe in any god- as opposed to just a person who didn't care about any god?
Also, if your god can only talk to you with signs that need interpreting, and wouldn't bother working with you until you'd begged forgiveness, I'm not sure that's a god worth following. Why could your god not just *ask.*?