Sounds like you're in the friend zone
We have a winner.
Go watch any romantic comedy ever filmed. This will explain the friend zone. (Side note do NOT watch the ending, this is the part where you the dorky douchebag gets the girl, this would not actually happen in real life though)
Honestly, find another girl. Turns out theres lots of them out there. And the less interested you are in her the more interested she will be in you. (frick I just gave you hope again and now you're going to avoid all this advice)