1.If you think "you have it". Well, among 1000 people, less than one is a writer. The other 999 are wannabe writers. To Want it and to Make it, is as different as to Volunteer and to Have to. 

2. Because your best friend did it. It does not have to be that way. We sometimes become authors for all the wrong reasons. Because we are too famous and too rich. Because we are academics. Because we can afford it. Because we have all the right connections. Because we took lessons on how to.

3. My hand is just writing all the time. That is most probably a painter's talent rather than an author's one. Well done! you just found your true calling!

Being a writer is a way of life, not a book. It is an everyday battle towoards that special person you want to become - that  u n i q u e  person. No water in your wine, no compromising, just growing a taste for fine books like other people grow vegetables in their garden. You are growing too, only that the game is transferred in the field of your mind. You learn to use rightly your senses: you see what others don't. You hear what others won't. You touch what others avoid. You speak what others are afraid even to think of. You erase, and you are the most strict crit of yourself. No one will tell you if what you wrote is no good, but your own taste. 

and for God's sake, keep on trying. Never give up.