Okay i really like this girl...?

i have known this girl for about as long as i have lived here (3 years) and i have liked her since I first saw her on the bus. she sat in my seat, we didnt really talk for a while, then she talked to me first about my brothers inviting her to their club house (they are younget than me im 18 they were 14 and 11) and i was confused as to why this pretty, popular girl was talking to me (i was reaaally sheltered as a kid and grew up not knowing the basic social interaction techniques that a 10 year old knows) so i was kind of rude and was just like yeah, uhuh. since then she has tried to be friends, she used to go to my youth group, and sit next to me, one time she sat really close cause she was crowded on the other side and i tried to give her some room and she said, oh comon i dont bite, in a playfull way. she had to stop comming to my youth group because her grandma (her mom died and she never knew her father) said she was only comming to that youth group because she liked a boy there. weve been friends, we used to text for like hours from like noon till night. so her first block in school was in the same gym that mine was and neither of our classes really did anything for the last quarter and we ended up talking alot. sometimes we would just stand talking to each other for like 30 min. one time we were playing go fish with some friends and we both went to move the deck and i accidentaly grabbed her hand and the deck and moved it, it was kind of awkward but she didnt seem to mind. then the next day her little sister ( a friend of mine) told her that i like her( the little twerp) and suddenly the girl stops talking to me, as much, seems kind of nervous around me like shes always wondering what im thining or something. we didnt really talk much and i kind of thought she didnt want anything to do with me anymore. then that big storm that hit alabama came (it was like a mile from where me and her live( she lives right down the street from me)) and when it started i got a text from her saying hi, and i was surprised she was talking to me, and prety suspicious too ( thats just how i am i never think anything good ever happens to me, cause it kind of doesnt) well we talked for a few hour texting, and then she stopped, i guess i got boring, and i thought it was her sister afterwards, the next day she comes by with a couple of our friends to borrow a movie and makes a joke about something that we were talking about the other day. i later found out that she had just broken up with her boyfriend like a day before she started texting me. the next day she volunteers at my church for a relief thing at the same me and those same two friends from the day before are, and works at the same job i was. we hung out for the rest of the day pretty much. a few days later i try to text her and she didnt reply, so i thought okay i guess were back to that then, and when i said hi at school she seemed nervous and ponderous as before so i though her hanging out with me and talking to me was just a fluke or something. a few days later she texts me and we talk for a while (god, i love talking to her, shes so fun to talk to) but i was sitting outside later that day after we had stopped talking and her and those same two friends( her sister included) walk out of my next door neibors house and her sister comes over and teases me about something me and the girl were talking about, so i assumed that she and my other friend had just put the girl up to texting me for ammusment. kind of made me sad. so, all of that to ask, what the heck is going on here, i have no freaking clue and i need some answers casue i have absolutly noone to talk to here.