So confused, please help me out!!

Here's my story, I was in a 6 year relationship with a woman who was slightly younger than me, we lived together for 5 1/2 years the relationship was unbelievable we were very close emotionally and we did everything together. Never any verbal or physical abuse between us and there was never any issues of trust between us. One night we were both drinking and we got into a heated argument and I got mad and sent a couple of texts to her sister in law who she hated, I was just saying things to her like not to trust her family because they talk about you and stuff, very dumb I admit and I regret it everyday. She broke up with me and made me leave the house, she still called me, texted me and wanted to see just about everyday after the break-up. This was 6 months ago, and up until last Friday we were very loving and affectionate towards each other, we were going on dates a lot and I was staying at the house again and all her family would say we looked so much happier and loving since the break up. However, we weren't officially back together but we were seeing what was happening and it was going great then suddenly last week see tells me she is talking to someone, I didn't really believe her because she had that personality where she always says things to people to see how they react and stuff. We kept seeing each other, calling and texting and sleeping together. Then see came to where I was staying to hang out we hung out for the night had a great talk and had a lot of fun then we went back to our house and slept together. Saturday morning came she was headed off to work gave me a giant hug and kiss and said she would call me later that day. She texted that night and said we weren't going to see each other but she called me before bed. Sunday came and she called me that afternoon and said she may be going out she did and didn't call me until a little after 11pm. She texted me the next morning being sweet, then called me that night also before bed. Tuesday she came to see me after a couple days and she was very happy to see me she was hugging me and kissing me. She called me that night and Wednesday morning. Wednesday night she called me at 11:30pm briefly still being sweet, I didn't hear from her until Thursday night until 7:30pm and she told me the guy she was talking too is now her bf. I was totally shocked and hurt things were going great. She's now been spending almost every minute of everyday with this and it's very fast. I think it won't work it seems definitely like a rebound thing to me and she has a very tough personality to deal with, I also personally think it won't last long because she obviously still has feelings for me and we still have the chemistry. I think it may have something to do with her youth. Am I crazy?? What do u think?

Seems very intense. It seems like rightnow she's playing games with you. She's trying to see how far she can go before you call it quits on her. If I were you I would set her straight by telling her you want her with you. But you have to let her know if that is not what she wants or if she wants to continue playing these games then you're not interested and you're leaving her for good. When she reacts you'll have your answers whether or not you stay or leave her. But she sounds like the type that you have to be firm and straight up with.