My girlfriend is angry at me for having slept with escorts, what should I do?

My girlfriend's first was me but before I was in a relationship with her I had been with several expensive escorts. She umed that there was no one before her but with the slip of the tongue, it suggested that there was. When she asked who, I told her about the escorts and she freaked out. She called me things like slime bag and left in rage. What should I do to mend things or should I even do anything considering we were not in a relationship when I did it with the escorts so she should have nothing to be angry about? The escorts were not cheap and at the time I wanted to lose my virginity before I turned 20. Afterwords, I kept coming back and tried others until I got into a relationship with my girlfriend and it is better than any of the escorts because there is actually love involved. I don't want to lose my girlfriend but I don't regret what I did before dating her. I was thinking about some make or break move like proposing or something. Any suggestions will be appreciated.