How do I break free from a haram relationship?

I was born Muslim and attended an Islamic school until first grade, so I learned the basics early on. I still try to learn as I go. I've never drunk alcohol, eaten pork, or smoked. But two years ago I started dating this girl, and it led me into haram actions that I'm ashamed of. She's cheated on me multiple times, and I saw it as a sign from Allah to leave, but I couldn't because I was too attached and scared of being alone. Sometimes I feel numb. Deep down, I want to return to Allah-to pray, to understand Islam better. I've saved many Islamic videos on TikTok, and they motivate me, but then she says things that pull me back in. It feels like a test from Allah. I want to cut her off completely, but I'm scared. Afterward, I feel disgusted with myself. I cry thinking about Allah and about a future where I'm a better Muslim, married and doing everything right. But then I wake up and see where I am now, and I feel stuck. We never know when our time will come, and that scares me. I want to get right with Allah before I leave this world. In my heart, I know my Creator and my religion. I just want to stop the haram before it's too late.