Girl very into me, now ignoring me?

Alright so, this is my pathetic attempt to get some type of satisfaction and advice.
Keep in mind while reading, I am a 20 year old male, and the girl I talk about is 19

Part1 of the story

Over the passed year or so, My best friends sister starts expressing interest in me. I have known her for years, and we have always flirted a little bit. I had never really acted on anything nor did I really want to, I had respect for the fact that it was my friends sister and hey that's just an awkward situation.

During june our families (and a few others) rented a house down in obx for a week. It was then that she was really laying it on me thick, and I had been getting proggressively more interested in her to begin with. She had a boyfriend at the time, but he was abusive and sleeping around, someone I knew from high school none the less and I never thought much of him. Things with her and him were unraveling fast before I even seriously considered dating her, by the time I decide to date her he is long gone - partly because I told him off.

I wasn't going to act on anything without first consulting my friend and letting him know what was going on in full, so we had a heart to heart and he told me that he actually WANTED me to date his sister because "I would take care of her better than anyone ever has" which I thought was a very noble thing to say. So I allowed myself to start getting closer with her during our time on vacation and we talked about things, I still (even after talking with my friend) didn't ask her out seriously or anything because I was still thinking things over deciding what was best.

We get home from the trip continue to talk more, I had thought it through by this point and realized that this was what I wanted, so I tell her how I feel, and that I really think we could have something, she agrees. We setup date(s) for the next weekend after discussing all that, she sends me edless text messages telling me how much she can't wait to see me over the weekend and all that. The weekend comes, I was going over to her house (also my best friends house) so I get there about 7 pm she's not there.. I hang out with my friend for awhile until she gets home around 12 midnight comes down, kisses me hangs out for about 30 min. Then un-announced leaves goes to bed. Next day I'm still there she's not home all day, doesn't come home till 12 again same story. I leave the next day, she's not there in the morning. So basically she planned out the whole weekend for us to hang out and isn't there at all when it actually happens.. I was dissapointed to say the least.

I decide maybe its time to affirmitively let her know how serious I am/have become. So I ask her out and tell her exactly how I've come to feel, you know.. That whole thing. I really expect her to give an enthusiastic response and be so happy that finally we would be pursuing this. She simply tells me "we need to talk in person" and ever since that, she ignores me completely every time I have tried to contact her, even though half of the times it was to setup an in person meeting so we could "talk in person" right? I would just go over but I have no clue if she'll be home or not.

Bottom line, recent events don't make sense AT ALL to me.. Lol to say the least. I've gone ahead and taken guesses that maybe she's getting back together with an old boyfriend and doesn't know what to tell me, or maybe there's just some other guy I don't know about or something - But I haven't asked her any of this, simply have persisted to try and talk to her and get her to tell me what's going on. Just to be clear I am not consistantly spamming her trying to get her to talk to me, Just enough that she knows I am wondering what is going on and that eventually we are going to half to talk.


SO NOW THAT YOU READ MY LIFE STORY (APOLOGIES) tell me what can I do? What could be going on? Anything.. I need people to talk to and I really don't know who to go to specifically for this. My parents are terrible dating advice since neither of them actually dated (they met when they were 12 and have litterally been together since then. I guess that crap isn't just movies? Lol)

Thank you to anyone who takes the time to read this and give me any type of reply! It means much.

- some guy.