Is God trying to tell me a message or something?

Im actually or was an atheist, but a strange thing happened today that i don't know why makes me VERY depressed. We'd a family meeting because of my grandparents 50th anniversary. There was my 9-year old first cousin that has endured a lot of difficult procedures at the hospital due to his neuroblastoma cancer. You can imagine how my father's brother and aunt have passed so long. Well, in the family reunion everybody (except me) said a prayer saying thanks to God for a "miracle" in my cousin because oncologists gave him like 7 or 10% or living. Then when we were going to eat meat my cousin asked me: you don't believe in God right? I didn't know what to say. That words are making me feel like sh$@t right now. I know this is kind of confusing to ask here at YA! but im so sad right now. I don't know why that comment has make me feel so bad if i've accomplished many things in my life, without God.