<human>: Give me the gist of the text in a nutshell

So this fuck up happened about a month ago, but everything came crashing down today.

Some background info: My gf and I have been dating for a while, and for a couple reasons (some my fault, some hers) we spent most of the month of July arguing. I was getting really discouraged with the relationship, and one night after a particularly bad fight, I got really drunk and sexted a girl I had been talking to/flirting with about a year ago via the app Kik. The next morning I felt like shit, but I told myself it wouldn't happen again, and I didn't tell my gf about it. 

About a week after the incident, we resolved everything and I realized my gf was an amazing woman, and my stubbornness had prevented me from seeing that. Since then (mid-July or so) things have been absolutely amazing between us, and I had never been happier. We got to the point where we were talking about marriage, kids, etc, and really thinking about a future together.

Fast forward to last night, I went over to her place after working a night shift and she had made me dinner. We had a great night, and before we went to bed I plugged in my phone to charge next to her. The next morning, I wake up to her yelling "WHAT THE FUCK" and holding my phone in my hand. She had tried to set me a later alarm, but since she's blind as a bat without glasses/contacts, she had accidentally opened up the Kik app and came across the messages I had sent to that girl a month ago. 

I tried to explain that it was a drunken mistake, but to no avail. My gf has a super strict moral code about these sorts of things, and she kicked me out of her apartment and hasn't talked to me since. On it's own, this might not have been as bad, but I'll be honest in saying that this is not the first time I've fucked up in this relationship (though it's the first time in my life I've toed the line of infidelity). I'm pretty sure there's no way I'm getting her back at this point.

If anyone has any tips to salvage this relationship, please tell me.
<bot>: drunkenly sexted a girl a month ago, my gf found out, and I'm pretty sure I've lost her for good.