He wrote because he was deeply perturbed by the deaths in his life. His main influence for writing was because of the people who were so near to him died. His wife, Virginia, was the inspiration for The Conqueror Worm, Annabel Lee, and one other that I can't remember at the moment... But as he experienced more emotional instability and death in his life, the more he wrote and the darker his writing became. Writing was kind of therapeutic for him.
He wanted to express his life through poem, or riddles. He is my favorite poet. He wanted to express the rough life he was going through through poems because he felt that was the best way to explain it
No one knows. What we know of Poe comes from three unflattering biographies written after his death all by authors who wrote novels the Poe gave bad reviews. They accused him of Laudanum addiction, alcohol abuse, and other scandalous behavior all unsubstantiated during his life. Poe had a hard life but millions with a hard life don't write a word so who can say how it effected Poe. He did upset his family by writing as a profession.