How do I get the truth from this girl? LONG QUESTION?

Simply said: Shelly likes Jacob. If Jacob doesn't like her back in that way, then she may decide to put her attention on you. You can get mad, jealous, and play whatever games you want. Or you could choose the higher road, and let Shelly see you're the better of the two. I feel bad for Tyra, she's stuck in the middle.