Is AUTHOR wrong in the post ? POST : First time posting and long time lurker and on mobile so sorry for formatting issues.

Anyways this happened really recently as in last night. I've been going out with this girl since valentine's and I feel like we've really hit it off.  Our convos are fun and I feel like there's no boring parts or downtime. 
So I took her out to dinner last night and she insisted on drinks after which I obliged. The beer was starting to make me have to go to the restroom so I went to do my business. However, on my way back I saw that she was on tinder and literally just matched with someone. 
I was in a bit of shock and quickly sobered up and took her home and I've been feeling like crap ever since. 
WIBTA for just ghosting her at this point? I don't think I've ever been disrespected like this in my life and just seeing her name pop up makes me angry.