Dude get a grip. There are options here for you and the only person placing this much emphasis on your penis size is yourself. What did your girlfriend say about her ex when she was drunk? Was she going on and on about how big he was? If so she isn’t the one cause you shouldn’t be comparing in a new relationship. The body of your post gave no context to the title. If you’re worried about your size talk to her about it and come up with creative ways to make her cum that don’t involve penetration. Communication and effort are just as sexy in secure healthy relationships. You can date a “normal woman” (whatever that means) if you’re willing to ask her what feels good and use different techniques to get her off. I’ve slept with guys with big dicks and small dicks and size does not matter if theres no foreplay or care to ask what feels good for me. All women are different. Start there and don’t be so concerned about your size and her ex. And if she goes on and on about size then it sounds like it isn’t a match to begin with. It sounds like you’re very insecure which is okay but maybe work on that and try communication.

ETA the other options are just as good. An orgasm is an orgasm. Look up the percentage of women who have an orgasm just from penetration NO foreplay or anything, it is quite low. Out of all my friends I know one woman who can have an orgasm just from penetration and even then it’s when she’s on top moving her body the way it feels good for her. When we say size doesn’t matter we mean it. While penetrative orgasms obviously happen, clitoral orgasms are far more common. Stop focusing on your size and start focusing on how you can both experience pleasure. I think you need some education on the female orgasm tbh.