Sam.
It sounds like you REALLY want this girl right

So muster up all your courage and talk to her. I know hello is sometimes the hardest word to say, but hey, that's okay. Two syllables my friend. You can do it

Maybe next time you two talk have stuff stored in the back of your head to say. Usually fixes the awkward silence.
The essential thing. She must know how you feel immediately. No more waiting!! You've stalled enough time! Go and get her! Run sonny! Find her! Seek her out! Call her! Find her friends and get her number or something! DO IT
xx