Does it count as her cheating on me that early? - Really confused at the moment

So... the last couple of days have been real weird and emotional for me. I had been lied and cheated in the past and I got to grow quite skeptical regarding trust. Not to say I assume everyone is a cheater, but I'll just make sure I got my back covered.

I am officially together with my gf for the past 2 months. While we were dating -pretty romantically dating for this time and age I'd say- we would spent 2 months getting closer as friends, flirting, taking long walks, dinner, go to each other's place but nothing more. We wanted to let it happen when the time was right. No kissing or anything whatsoever.

By the end of those 2 months of dating , I confessed that I'm really into her and that I'd like to go on with this into a relationship. She then told me that she didn't know if she was up for it , because she was afraid to lose the friendship in case it all went bad at some point. I told her that it is completely fine and that I'm a man that can take no as an answer and realize that the world doesn't end there.

A few more dates and hang outs at mine and her place took place until I finally told her that it's just getting too much for me to keep it this way because I'm developing feelings and sexual tension towards her and that it should better be over now before it's too late for the both of us. At that time, she had already planned a 22-day trip abroad with a girl friend so she texted me a long message about how she wants to keep seeing me, that she is feeling things for me and sexual attraction , that she doesn't want me to forget her, that I should wait for her to come back and that I was of course free to do anything I wanted by the period she would have been abroad but insisted that her, herself wouldn't go for any other man until we found out where we can go with this together.

I did believe her, wished her a nice trip and patiently waited it out. She came back, we made out, had sex and decided that we wanted to be together.
2 months have already passed and everything is going great. Last week she had to go visit her parents and she will be back in 15 days. We get to talk over the phone, skype etc every day. We even arranged that I go see her there in a couple of days from now.
Now. All was good until last night she told me that there's something I need to know about her.

She said that when she was abroad, she went out with her friend and two males that they had met there and while at the bar, the guy kissed her. She said she kissed back for a while and ΗΕ wanted more but she stopped him. She got really disgusted by him and the thoughts of me being back here that she knocked it off in a short period of like 5 mins and ran out with her friend.

When she told me, I got really upset about a few things.
First of all, why not tell me in person? Telling me while being so far away with the fact that I cannot face her and see her body language and expressions is upsetting.
I got really upset about the fact that I wanted to have known just when she got back, before we started anything because I wanted it to be MY decision to go through and keep it going with her after I knew that. I was left with no choice. I might had been okay with it , I might had not. I wanted to be able to make my own decision.
The third thing, is that I had believed her and kept the text-promise she had sent me on her own. We didn't have "anything" officially but it was 2 months of real close dating (spent 12-hours together etc) and I had confessed to her about my feelings and got the "please wait for me" answer.

She said she's really sad and that she wanted me to know before I went to visit her , in case I want to change my mind now on our relationship. She had known that I'd been cheated in the past and I'm really sad that she went through with that random guy at the club. She said that she doesn't want to lose me and that she'd understand if I don't want to give it a chance.

I need advice on how to see it and how to actually react to it at the moment. It's really hard for me to trust people and I've had counselling in the past regarding trust issues, I'm not afraid to say it. I had made plenty of effort and saw actual results of this but right now it all comes back to haunt me again. I do not label it "officially cheating" but it does hurt pretty much the same. I'm sad, upset and confused.

Hope it all makes sense.