JWism filled a void - but what void? A desperate longing for absolute certainty? A narcissistic fear of death and the unknown? An insecure neediness, to feel that somehow we are special and chosen, while the rest of mankind is in darkness?
Yes, I feel the emptiness too since leaving the JW's. It is the emptiness born of realizing that I am no different from anybody else. That while I have a certain amount of control over my own life, that the vast majority of factors affecting my life are beyond my control. It is hard to articulate exactly why or how, but JWism gave me an illusion of total control. That if I stick with the org, then everything will turn out allright.
Alcoholism, drug addiction, and religious fundamentalism all serve the purpose of "filling a void" - the void of the unknown. Life is harsh and uncertain, and it was this unpleasant reality that JWism countered with its promises of paradise, promises that never come true, though they are continually presented as coming "any day now".
Leaving JWism has forced me to see myself for what I am, which is painful indeed. I thought I was so special, that somehow I was more holy than the unenlightened masses. In my own mind, I was the center of the universe (much like Russell, who I identified with strongly when I initially became acquainted with JWism).
A doctrine insulates the devout not only against the realities around them but also against their own selves. The fanatical believer is not conscious of his envy, malice, pettiness and dishonesty. There is a wall of words between his consciousness and his real self. - Eric Hoffer