Someone I love is a virgin and I’m not. She doesn’t want to start a relationship with me because of this. Why can’t she let go of my past?

Plenty of people won’t date virgins. Why won’t they let go of their insistence on sexual experience?

See the irony? People’s preferences are their preferences.  Often those preferences will exclude you as much as they include you.

The only information that’s relevant to you is that you’ve been rejected as a potential lover. Accept this and move on with as little rancor and regret as possible.  There are people who will see your previous experience as a point in your favor.  Go date the ones that want to date you.