question regarding breakup - need advice?

Here is the situation. Me and my girlfriend brokeup a couple of days ago. She has a friend from Austin who is visiting this friday. This is a guy she dated one time and apparently nothing came of it because the distance was too great. She asked if I was ok if they went to dinner. I was 100% ok with the dinner because I trust her. Apparently the guy had asked if he could stay the night at her house Friday vs. driving back to Austin. I told her I fet uncomfortable with it. Later in the conversation I started overthinking things and told her I needed a few days to think. She took that as me walking out and as a result said she could not be with someone who walks out when things get rough. My question. I know my actions were wrong and is it possible to win her back because I really fell for her.

Maybe you should ask her if she wants too get back together and when you said that you needed time too think you didn't mean you were going too walk out on her. But if you too do get back together just ask if you can stay at her house for the night while the guy stays there. Good Luck.