Any idea what's going on?

Hi folks,
I really don't know what else to do so I'm hoping someone here can help me

A few weeks ago I met this girl and we went on a few dates and it was going well. Then one night she invited herself to stay over and we had a really sweet time and we slept together. I thought this all went well. I was sensitive, caring, put her first. And she even said things like that she thought I was great and that she felt safe with me. Thing is, she is incredibly insecure and keeps talking about how her old boyfriends screwed her over so I have kept this in mind before I've done anything. Maybe I've been too cautious. They day after she asked if I anted to see her again, obviously to which I replied yes. Anyway, it's been 2 weeks since I saw her. I asked her out a few days after and she said she was busy but didn't say when she was free. A few days later I asked her out again and asked her if she didn't want to see me again. Then she got quite angry and said I was being impatient. She also said again that she was busy but again didn't say when she was next free. I don't know what is going on anymore. I mean, I gave her the opportunity to tell me she didn't want to see me anymore so why wouldn't she say so if she didn't? Do you think she is seeing another bloke and keeping me as back up? Is she just trying to upset me or make me jealous or something? What do you think is going on? These questions are starting to keep me awake at night so any help is much appreciated

Thanks in advance