Girlfriend doesn't want to have sex with me now
I am a 25 year old male. My girl and I have been together only a couple months. We have had sex twice now. I lost my virginity to her, she has had a couple partners in the past. After we had sex the second time, she tells me we need to stop having sex for a while. She says she starts kind of in the mood then she loses it. I know this is most likely cause I'm not experienced. She then tells me when we have sex, she can't stop thinking of her ex from 7 months ago. She says he did things a certain way that I am not but she won't explain what she wants and just tells me to read a book. What am I doing wrong or what can I do. I know I'm new to this but she's kind of throwing it in my face that I'm not as good as her ex. Any advice?? Please help!