I'm trying to think of what I am doing.
Are you trying to find something worth doing?
I really don't know where I'm going in life. I feel like I'm not even human sometimes.
Feeling lost in life is something everyone goes through at some point in their life. There's nothing wrong with it. Just keep trying different things and keep moving forward and you'll eventually find what you're looking for.
I feel like life might mean nothing since no one can prove god exists.
It is good to challenge your beliefs. See this as a way to motivate yourself to explore and discovery what you believe in. Take this opportunity to strengthen your resolve and learn more about yourself.