What to do? (Possible unrequited love)

[fusiler]

I'll give a little background so you can understand what I will tell: I have a very good friend of mine, actually we are best friends and we know since age of 3... So, it's like 15 years of friendship, that we always kept alive.
In the last time we've been out together so much time and I think that we got to know each other better (Yeah, sounds pretty weird to say after 15 years of friendship), and since then I think that my vision of her has changed radically... I think I fell in love with her. So, that is probably a big problem... But I would want to turn things a bit and try to form a relationship with her... Could be that possible? Or do I have more chances of ruining a long lasting friendship for nothing?
I noticed changes around her too, we are talking a lot and I notice that she feels more confortable around me tan ever before.
I'm pretty shy, and never had a girlfriend/kissed/etc so it's pretty difficult to me to try. What should I do? I freeze instantly even when "breaking" the touch barrier (not much touchy-feely at all with my friends), so you should take an idea of my personality.

Thanks in advance for the responses and sorry for my abad grammar, but english isn't my main language.

[basilandthyme]

Hi Fusiler, your English is fine

Unfortunately, you're going to have to make some type of move if this is going to go anywhere. The fact that she's seeming more relaxed with you is a good sign. Do you trust any of her friends enough to talk with them and find out how this girl feels about you?

[fusiler]

Hi Fusiler, your English is fine

Unfortunately, you're going to have to make some type of move if this is going to go anywhere. The fact that she's seeming more relaxed with you is a good sign. Do you trust any of her friends enough to talk with them and find out how this girl feels about you?

Actually no, since we have totally different group of friends, and I really don't know them too much, and neither them, so I can't get any information of them.

[fusiler]

So, yesterday night I went to the Cinema with her and with her brother, and it just was awful... Everytime that I would want to get a little closer (I didn't want or expected to kiss her for obvious reasons), she would get a little closer too, but I noticed that she was uncomfortable with it, so I desisted mid-film from that possibility and just watched the movie..
I think that it is very unlikely that she would like me as something more than a friend.