GF showed my dad some messages I didn’t want him to see

She lost my trust, I’ve shown her and only her some messages my dad’s wife sent me a couple of months ago, where she was insulting me for “ruining her marriage”, I didn’t want my dad to see the messages because I didn’t want to cause any more drama.

While we were on a trip a couple of weeks ago, my gf unlocked my phone and showed my dad the messages even if I told her I didnt want to. My dad got mad at me for not showing him the messages before but didn’t say anything else for the rest of the trip. I got really mad at my gf and had barely spoken to her since.

The thing is that my dad and his wife are not in a good place now, Clara has already moved to her parents’ and my siblings stayed with my dad, according to my dad, this is a break “to re-think the whole relationship”, but I feel like garbage, my dad seemed so happy before I told him why I hated his wife and now this has just gotten worse, it seems like I destroyed my dad’s happiness and which is worse, my siblings’.

My dad says this isn’t my fault and that I’m the one who has to forgive him but that doesn’t prevent me from feeling like if I destroyed their happy family life.

I don’t think I can trust my gf after this.