Broken trust

I have been lied to twice by the woman I love.

Let me tell you my story. There was a woman I was interested in, and I asked her out. We became a couple. She's the type who doesn't show her emotions and focuses mainly on her objectives, while I was the opposite type (taking care of her, showing my love through multiple ways). We always had some quarrels about a friend she had (male), let's call him S. S was her childhood best friend, and they were always together, doing everything together, which was okay in my opinion when I wasn't in the picture. But now that I am, I requested that she give some of that time to me, as she was supposed to do those activities with me now (or else, why am I her boyfriend?). With a lot of communication and talking, she accepted.

Months later, I heard from one of her friends that she had been out with S and talking about me in a way that I'm not even her boyfriend etc، I confronted her, and after a long conversation, she said it was true and apologized. At that moment, my trust in her (which is necessary for a long-term relationship) got broken. But I loved her so much that I was ready to bury this pain and start again. Before accepting her apology, I asked her one question: "Is that it? Is there any other secret that you didn't tell me yet? Please just tell me everything now." Her response was no; there was nothing.

Months passed, and we had other quarrels about the same S. At one time, he gave her a red flower (she loves flowers), and another day, she told me that he was interested in her (in the past). I tried my best to stay calm and explain that all this hurt and it's not okay. Months passed again, and one day when we were doing our stuff, she didn't want me to kiss her. I was confused, and later I asked why. She said, "Well, I kept thinking about a bad memory. To be honest, my first kiss was with S."

This one was very painful. I didn't know what to do; I was so devastated by all this time that she was lying to me (she always said I was her first kiss). I am super confused and traumatized. I love her, but she keeps lying to me. I love her, but Ishe don't want to stop seeing S. I love her, but I don't know how I can trust her again. Please, can someone help me just understand how I can get through all this? Thank you for reading this."