girlfriend called me by her exes name

Yesterday my girlfriend called me by her exes name and it’s really upset me. even after discussing the issue i’m still hurt and don’t know how to stop feeling that way. a bit of background: my girlfriend and i have been exclusive since february and official for about a month. Yesterday, in causal conversation she called me by her exes name. it really caught me off guard and i didn’t know quite how to respond as this has never happened to me before. my girlfriend tried to brush over it but i had obviously heard what she said. she said that because our names our similar (Caylen and Kenlee) it was just an accident.

We spent the next several hours not talking (more of me not talking to her). i was constantly having to fight back tears so i just avoided speaking/looking at her. i can’t quite explain why I wanted to cry. i don’t think she’s cheating on me. After awhile we went to target and some other places and went to go paint. I had also found out i didn’t receive this position at my college i was hoping to get. My girlfriend suggested we go paint outside. i was kind of hesitant because it was windy but i agreed anyways. about five minutes in the cup of water we had brought out to clean our brushes with splashed all over me, my phone, and my canvas due to a gust a wind. my girlfriend laughed and i got really upset mainly due to my phone being soaked in water. I started crying and walked back to my apartment leaving her outside. i really didn’t want her to see me cry as she had expressed before that people crying around her makes her uncomfortable. i got changed and laid down in bed still crying and she came in and tried to comfort me.

when i finally collected myself she asked if I was upset because i didn’t get the position i wanted. i told her no and that i had been wanting to cry since that morning. she said understood and would be upset if the same thing had happened to her. She apologized again and said that she wasn’t thinking about her ex when i was around or speaking to her. she tried to explain it away again however, trying to recall what we were talking about when it happened. (i don’t really recall but i’m pretty sure i was talking about stuff related to the position i wanted) and she wasn’t sure but said that she thought she was about to snap at me and was so used to snapping at her ex that’s why she said. she hasn’t snapped at me during the time we’ve been together and i don’t think she was then. this is the first issue we’ve had so far.

i’d just like advice on how to approach this issue/ how i’m supposed to move on from it. do i bring it up again or do just leave it?