I just need to know someone is there

Last night I was spending time with my girlfriend, and she was showing me a video on her phone. A message popped up, and it read "you have a bf though?".
I realize how bad this looks. We haven't been dating for very long, but I FELL HARD for this girl. I have only had 1 other "real" relationship, and it was the entire 4 years of high school. She didn't treat me right, and cheated on me multiple times, and I knew. I didn't care, I was a stupid high school boy. I haven't even considered dating anyone for 5 years, until I met this girl I'm dating now.

Back to now. I became pretty set in my ways. NO SECOND CHANCES. I will not be hurt again like that. After I seen the message I didn't say anything. I didn't really talk for about 10 mins. She noticed I was being quiet (because I was totally lost in my thoughts). She understands how bad that looks. She immediately text back that person (who was also offering her a career) and competely told him off. And we talked about life, and love for about 4 hours.

She has been through A LOT she has been beaten by boyfriends, cheated on muptital times, and in general treated like shit (similar to how I was treated). We are both 23. Her family absolutely adors me. Her grandma told me some of that stuff, before she did. All of the family I have met, says I am the only one who has treated her like this, and that she is truly happy for the first time in a long time (I was raised to treat a woman like a princess, and I live by that.) I LOVE this girl, and now the only thing going through my mind is that. I'm trying so hard to give her the benifet of the doubt. She has been through that pain, why would she do it to someone else? But on the other end, maybe that's how she thinks things work now.
I didn't see the rest of the messages, I don't think it's my place to look through a phone no matter the cercumstance. And like I said I'm trying to give her the benifet of the doubt. It's just hard, because I cant go though that pain again.

I'm not sure what my question truly is. I mainly needed to get my thoughts out of my head. Thanks for reading. If you don't have much to say, please just let me know someone is out there, that understands.

You said you talked for hours after that message popped up. Did you talk about what it was? Did she explain? I think you should simply talk about it and maybe it's not at all what you are thinking.

She explained it was nothing, just someone who was nice to her, and was expecting something a little more I think. To be honest, my mind was not paying attention to what she was saying. But I know it made sense, and I understand what she said at the time. I just couldn't get over all of the old feelings of my EX cheating on me, and I was silently freaking out in my head. I want to belive it was nothing, it's just a doubt in my mind now. And I'm trying really hard to get over it, because like I said I love this girl, and I have never felt this way about anyone before

This is a bit hard on you . and I feel what you feel man . I am sorry for you . just hold yourself and behave well .I think because she used to be treated like a shit , beantten an cheated over all that why she might her feeling died that why . and you are a man you can create her . you can bring brilliant life into her life . do your best , learn how to steal her attentions . find your own ways . you have a mind , a brain and an immagination . if you could do nothing at least just look up for jokes , romantic quotation . make her smile every single day and try to push her into your life kindness , carring , feel her she is a princess . just try and stop complain and grumble . and be optimistic . and if u need more help . just contact me I would love to help you . Thanks for sharing your caring wid us