Crazy Girl Problems?!?!?

Okay so me and this girl i work with have a thing for each other. She tells me she cares about me, and she really likes me, and i really like her too, Thing is, shes crazy. One day shes all fine and happy next thing shes mad at me for no reason, i try and talk to her when shes mad but she wont have any of it. Also she has alot of guy friends, and hangs out with them alot. I feel like everytime i try and hang out with her she blows me off, i mean if 2 people like each other they should try and spend time with each other, right? For instance yesterday i asked her if she wanted to chill or hang out, she said she didnt know, but 2 hours later she calls me saying shes going downtown with some guy she just met at work the same day, they started at 11 at night and stayed out till 3 in the morning, i know this because she called me at 4 AM to tell me about her night, and what they all did. I mean im not the jealous type, but if i want to hang out and you go out with some random dude, what does that seem like? i dk if i should be mad, or what? I mean we have no title, were not together. should i ignore her? oh and she craves attention. she tells me she doesnt care if i talk to other girls, but i know she gets mad when i do. shes the type of girl who can drop somebody real fast and forget about them. And the other day, she told me she thinks we need some space, so i said okay thats fine. Then she blew up saying she was going to delete my number and all this, and i asked her what was wrong, and she said i took it the wrong way!!!! I mean what is that?? I dk am i overreacting or what?