If there's no God, will anything matter anymore?

When I was a Dub, I used to believe in a creator simply because it seemed logical. The Society's books explained logically why the Bible was God's word, why it was simply logical to believe in a Creator and why the theory of evolution didn't make any sense.

I was happy "knowing" there was a God, because that meant there was a higher being out there who was interested in us human beings and who would ensure justice would eventually win. At that time, I was also very interested in the wonders of nature because I felt they all had a purpose. I was thrilled at the idea I could live forever and study the nature endlessly, maybe even visit distant planets.

When I lost my trust in the Society's publications because of blatant misquotations and twisted logic, I also lost the basis of my faith in the Bible. I know some ex-Witnesses don't lose their faith in God or even the Bible, and I'd actually like to be one of them and live my life the way Jesus actually meant... but I don't think I can believe in that stuff anymore.

I began thinking, if there is no God, and this life is everything we have, nothing really matters. Why should I be interested in things like protecting the nature? When I'm dead, I couldn't care less whether the human race will destroy itself or if the sun will explode and destroy this race. If there's no God, even the existence of our solar system won't matter.

As a result, I've lost my intellectual curiosity and interest in studying the nature. Partly this might be because of depression, and if it is, I'll probably gain back my interest while I've gone through the healing process. But right now, I've been indulging in pleasurable things that don't really matter: enjoying good food and fine wine, great music, partying, fantasy... I've been busy distracting myself so I wouldn't actually have to think about the meaning of this world and the stuff that really matters.

I'd like to dedicate my time for something significant that would actually help people and the mankind. But none of the causes I could live for would last forever. That's why I'd like to dedicate myself and my time to God, because God would be something eternal, so my work would have an everlasting meaning and purpose. But if there is no God, will I ever find the same kind of meaning in some secular cause?