My girlfriend keeps lying and hiding things from me.?

My girlfriend and I have 6 months going to 7 and we have history in our relationship, she is a sweet girl who catches a lot of attention because of her great personality, especially guys and guys confusing her sweetness for flirting and we all know where that leads. So in the past time when we were talking and getting to know each other we were kind of deep In the relationship already. To the point where we were friends and gave kisses to each other on the lips. So at this time she had this guy who gives her his undivided attention, he likes every photo of her in instagram, he gives her flowers, chocolates, takes her out to eat (1 on 1) and I told her if she is interested in me then this guy is bad news for us. She didn't understand so she kept on hanging around this guy. Which I kept warning her about it, but she didn't do anything about it. It bugged me so last time I told her we got into an argument of it which lead us to separate and not date anymore.
So a few months later she admitted her mistakes came back to me with restrictions because she told me this guy ended up confessing to her (she rejected him of course, and this guy still kinda communicates with her till this point but she set restrictions). So that's one problem she lied to me about she told me she stopped talking to this guy and I caught her once talking to him still.
Another problem is that we set boundaries in our relationship where she didn't want me to smoke, and so it wasn't fair in my part to give up something without her giving up something herself, so I told her to give up her clubbing (partying) because it isn't healthy in our relationship. So at some point she lied behind my back and went out clubbing. I was upset...
So point being, today I caught her lying to me again and her posting pictures of her clubbing after she told me she was going to a friends bday dinner. I'm kinda upset because she keeps doing this in our relationship
What can I do to fix this? I'm scarred from her lies
Updates
+1 y
Thank you all for your response, I guess I'm coming to conclude that I might move on, but I guess being in a lot of pain is just tough. I loved that girl, but i guess we weren't meant for each other.
My girlfriend keeps lying and hiding things from me.?
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