Life, God, Beliefs and failures

Sometimes I think do we have any purpose in life? I mean its interesting how we can choose everything(Yup, we can!), like even our purpose but what's the bigger picture? I used to think that there is something grandiose which I'll do for the world, its not that I don't want to, but I simply don't know if I will. Some months ago, I failed in a semester exam, which never happened in my life because I was always the topper kind of guy but then boom! this happened. I was in complete and utter shock because I used to think that this can't happen to me, I am a good person, but I was simply wrong, in fact I was just a normal regular person who was existing in this world that's it. The first thing I did was to take control of the situation since the marks could have shaken my placements so I decided to gain some skills (which I properly did btw). That day I realized that there's no god(I don't call myself atheist, neither does it matter) and everything, each and everything was my choice which led me to this - the so called Butterfly effect! When I used to believe in god I used to think that someone always has my back, and that made me dependent on god and not on myself. That day I realized that how fragile my career was that a professor who doesn't even know me properly can just fail me in a snap and I am sort of done for the year and I'll have to do a hell lot of work! I realized that not believing in god made me stronger(maybe different for other people and I totally respect it) and it led me to gain skills and be better. That day changed my life and it was one of the best(sort of worst) experiences I've ever had. When all your beliefs shatter and you realize that everything was your choice and it led to this. After that I fell in love with coding and started doing Web Development properly and eventually got good at it, and currently I am learning more and more. That experience made me more self reliant and confident. And most importantly it made me realize that purpose can simply be chosen, although, it came from a preacher I came across a few months ago, named Jiddu Krishnamurthy. He is a very prominent preacher and has helped me in several ways too.