Hi NoChildSupport, I'd say that it's completely understandable if you're feeling scared, anxious, vulnerable, powerless, betrayed, threatened, desperate........all those things and more
But this just kind of evidences how important it is for you to move away from this person, right??
And this isn't the only thing they're going to be holding over you, right?? This isn't the only thing in the "relationship" that makes you feel powerless, "less than"...........??
So time to relinquish this power they have over you, hey??
This relationship (from what you've said before) is likely to be way more damaging to you in the longrun, than if you moved away from them and let them do what they want with the texts.
I know it must seem so scary to you having the thought that other people may see them..........but there was a genuine reason you were sending those texts, right?? You were feeling insecure, vulnerable, desperately wanting someone to care/to understand/to be there for you............??? So if you can try not to judge yourself too harshly on having sent those texts.............and anyone else who judges you harshly if that person were to show others, well they're not going to know the full situation anyway, right?? You've nothing to feel embarrassed about, you were hurting.
And now, it's where you go from here.........maybe working on gradually developing more "healthy" relationships, with people who are going to be supportive, who are going to "empower" you, who you are going to be able to trust???
And maybe, on finding some of that inner strength (which I know you have!! ) to help lead you past this "relationship" and to not need anyone that much.

Alison