I don't understand what happened with her please help

I'll try and keep this short. But we got so close, she told me everything, came to me for everything, told me secrets she never told her best friends. She trusted me so much. We started showing so much affection, We started kissing and making out, and sleeping in the same bed. We ended that because she didn't want a relationship while in college, and it was only right when dating. Before she would compliment me, acknowledge my compliments to her, sneak off to the bathroom at work just to say hi, when she didn't live close she was so excited when I could come visit. Now I just found out she has feelings for someone else. She says she still cares about me, and has feelings for me, and I am still amazing and I didn't do anything wrong and feelings just come up. She said feelings just change. She says that maybe she'll figure out I am the one to be with. She has told me before that I am the kind of guy she has been looking for, and can be how she wants to be with. She doesn't know why she likes this guy, and says it could be just a phase, and may still end up with me.

How could she be so close to me, care about me so much, say she likes me and wants to someday be with me, Do things with me like the making out even though she is totally against that outside dating, and sleep in the same bed as me because she trusts me and knows I won't do anything bad, then just like that lose feelings for me and gain them for someone she has known for 1.5 months.

She sounds like she dosen't know WHAT she wants., -And while seeing you, she looked over the fence and thinks the grass is greener over there.
I would try and not get too much more attached to her, she may just let you down again.

There are obviously qualities about you that she likes, but there is something about you that pushes you into the friend zone and she's trying not to hurt your feelings I guess. It's hard to tell over the internet, but that behavior is very strange.

This is like the 9th repost of the same thing. Instead of posting the same vague question over and over, why not write one well written one with details so that the regulars can at least try to help answer it?