My girlfriend absolutely refuses to orgasm
So I've been with my girlfriend for about 5 months, and I love her very much. Our sex life is great, we have sex quite often and we both have a lot of fun. Only issue, is that she has never orgasmed in her life, and she refuses too. There are times when things are going well and she stops me because she feels like she's "about to pee" (which I heard is a common feeling for women who are about to orgasm, correct me if i'm wrong). She didn't let me touch her clit until like 3 months in and she only allows me now because when I did she really liked it. She will never let me give her oral despite the fact that one time she let me go down on her she was in the most pleasure that I have ever seen. She won't use toys, won't do anything that leads her to cum. She says she's embarassed to cum, and she feels to vulnerable, which I don't feel like is fair because I lost my first time to her and I let myself be vulnerable to her.
I don't want to be someone who pushes someone to do something sexually that she doesn't, but it's really difficult to fully enjoy sex when she never finishes. Every time I bring it up she gets mad. She says it could be a psychological thing but she refuses to do anything about it. I feel immensely guilty every time we have sex because she never finish. Is this normal for girls to do this?
EDIT: Also, she's never masturebated and only started getting sexual recently.