The playwright, William Congreve gave the language several famous quotes. One is “Music has charms to soothe the savage breast.” Another is “You must not kiss and tell.” But the Congreve quote that applies to you is “Married in haste, we may repent at leisure.”
When we make a mistake, it’s not about hurting others; it’s about doing what is right. Some people know you don’t want to marry her; tell her before someone else does.
Take the blame on yourself; man-up to what needs to be done moneywise. That will be nothing compared to having a life and a wife you do not want.