Good on her for admitting it. Poor effort on your part thinking you’re the victim here. She’s probably been stressed, worried, anxious, etc about this and all you’re concerned about is yourself.
Why not support her through what could be quite an anxious time and see how you can help address this.
An ex of mine had a few payday loans as she wanted to keep up with me (dinners out, lots of drinking). Once I found out, we dealt with it by staying in more, cutting back on some things and got her debts paid back. Found the underlying issue, discussed it and dealt with it. Never thought less of her for it. Why did your partner run these debts up?