Girlfriend Cheated

Hi,

For first Six months everything was great with gf we went on holidays and no fights or few issues if any. Then she started name dropping another guy (who broke up with his gf of 9 yrs) and liking a few of his pics on fb. I never mentioned this as didn't wanna seem insecure.
For the last 3 months we had been fighting more when drunk, she felt I didn't trust her and was maybe disappointed I wasn't living my life and focusing too much on her ( although she never said this) I was annoyed she couldn't talk about things openly and always seemed to be hiding something. I told her I loved her first she said she liked me twice in 10 months I think. She met my family but never met hers. She always responded straight away to txts and wud call/txt me a lot and make cakes for me so was def getting mixed signals from her. We saw each other max 2 a wk, but only more if I initiated it mostly.
Things had got to cinema dates no sex and getting defensive so I'm my gut knew she was prob cheating. It seemed she was avoiding me more aswell. The thing is she was still trying to plan hols with me and talking about my bday etc a year away. I logged onto her fb and saw flirty txts to that same guy and then a poke by her a few wks later. The following day she couldn't look at my parents and rushed outta my house. I dumped her soon after ( no sex in 4 wks prob) I felt she d def cheated or was gonna and didn't wanna stick around.
My issues are why did she cheat? How long was she cheating? Did she ever really like me? How can she be so cruel to keep me around while sneaking around with this other guy? How long was she gonna keep me around before she dumped me/ why make future plans. How can she live like this. There's been NC for a week now and I'm not gonna contact her and don't think she will either.
What's she thinking now will she be happy or sad? I know I'm gonna have to move on and learn from all this and meet someone who cares more about me
Thx & appreciate any advice/thoughts

Always and I repeat ALWAYS listen to your gut feelings, don't ignore them, it doesn't make you insecure they protect you.

I don't know why, because she is selfish, weak and has no self control, why I think most people cheat, because cheating is a choice you make, some people blame drinking or drugs on it, but to me it is still you making excuses for your bad choices regardless, you wanted it, so you did it. She might have liked you in the beginning and then he came back into the picture and she got tempted. She maybe was waiting to see how things went with him before she left you, cruel but it is what people do, in-case the temptation doesn't pan out, they have a consistent backup partner.

Don't contact, only discuss if she reaches out first to explain things. Sorry you are hurting.

Thanks for advice u sound like a nice girl.
I think if I had of brought up the issue early on she wud have played it down said were just friends and said don't be insecure. It's a tough one. She always had an answer ready for everything aswell. Looking back I think she was maybe playing me all along. Would you agree?

Didn't like logging into her fb but felt it was the proof I needed to let her go. I made mistakes aswell for sure but part of me thinks even if our relationship was perfect she wud still have been "looking around" as she slept with me on 1st date. (Not a good sign but I really liked her so wouldn't have listened to anyone) I was considered much better looking than this girl so whenever I complimented her about looks she never believed me and said what are u doing with me before aswell.

Would a girl who really likes u normally tell u they love u within 10 months and want to be with u a lot more than once a week?
I'm gonna try working on things I did wrong and pick better gf nxt time!
My mistakes were been too available, not having enough going on in my life, no obvious LT goals or plans....I should have been more of a challenge and toned down compliments and affection towards her. I was trying to fix these things but was too late. The affection thing I find hard to tone down though when I really like someone I wanna show them a lot. What should I change about myself? Was the running out of the house from parents her reaction out of guilt?