The only way to know for sure is through time and exploration on your own. Its perfectly okay and normal to question religion and to explore other beliefs. It will either strenghen what you already believed before or give you a new insight on a new path of a different religion. Take the time to read about and study other beliefs and find what feels right for you personally. No one else should infulence your decision, afterall, religion is your personal beliefs.
It's 100% normal to question your faith at times. I think that figuring out what you believe in takes time, though; sometimes it takes one person more than others. Some people are never quite sure. What's important is that you always keep your mind open, no matter what. Give yourself time, and don't feel bad for whatever you decide. At the end of the day, only you can decide what you believe and what you are.
It depends. In all peoples spiritual walks there are highs and lows. If you were a believer before you may just be going through a low :)
when you can "fu*k you god" & not be scared, you're an atheist alright.
I see no sense in that type of reason.