what is reason behind my existence?

ok before starting I am good at science. so, I believe in existence **Allah** The creator of us because science doesn't always ends with dot it will ended as comma. Few weeks ago I was on bus and saw a man who pulling cart of load. It was pity site that he was full of sweet the load might be above 50 or 70 kg which used to pull by cow but he is pulling it all by himself. then a question appeared on my head. I heard Allah was kind hearted person than anyone then why..? me who doesn't work that much and always want help someone but i can't living a good life but why he doesn't deserve it. I started to doubt my own existence and it's aching my head till now. can someone tell me why this all