how do they do it?

I've been trying to write a story that I already had in my mind for over a year but I everytime I start to write it, I ended up always stuck in the same lines . It's like I'm pretty sure I have this ability to write something, not that I'm being too confident about it but I feel like I know I can write something.

I believe in myself that I can do that, I can write a good story, that someday I'll publish books as many as possible but I kinda having a hard time to make myself stand for what I currently doing, to stay focus. well that's definitely my weakness, I get distracted soooo easily. And I hate myself for that because I know someday I'll regret it.

Honestly, I've never thought I could've so much interest in writing since I don't really like reading a fiction, I prefer reading biography or journal, something real. But then out of nowhere, this feeling just bump into myself, I got so much interest in writing, very passionate. Well nothing in this world could be as easy as lay down and doing nothing, right?

So, I've tried to write several short stories which is actually, thank God, people love it and makes me wanna get into this writing things even more. But I've got few problems here, like the opening, I don't know how to start the story, I'm afraid It'll make anyone who read it boring on the first page. You know the first impression so important, right? That's why I hardly to start to write down my story even if I got the whole idea about the stories from begining until the end but instead I just well let it go, the whole idea because I don't really know how to start it.

Can somebody tell me how to do it?

I really. REALLY. wanna make good stories that anyone can read and can tell their friends that "THIS is my favorite book. It changes my life." because I barely think or say some particular books are so freakin good but when I do, that book must be more than a book for me.

Do you think I think too much about the result instead trying to write?