Should I leave my girlfriend and look for someone else?

I’ve been with my girlfriend for 4 years. She’s incredibly loyal, loving, emotionally available, and has always treated me well. She never expects expensive gifts or dates and loves me a lot.

The problem is that I haven’t treated her the same way. I’ve cheated on her, lied to her, barely given her time, abused her, and made fun of her. Yet she still stays because she loves me.

Honestly, I don’t think I love her the way she loves me. I’ve mostly stayed because she’s such a good person. But whenever she blocks me or leaves, I become anxious and start missing her badly.

My main question is: Should I end this relationship and look for someone else who I might actually love, or am I making a huge mistake by letting go of someone this amazing?

I don’t want to stay with her just because she’s good to me if I don’t genuinely want to be with her. What would you do in my situation?