I lied about why I broke up with my ex and it’s been messing with me ever since

I was in a relationship with my ex for 2 years and I broke up with her about 4 months ago. My ex did absolutely nothing wrong and I couldn’t think of any other reason why I wanted to break up with her other than I just didn’t like her anymore. It’s all I could think about, how much I didn’t like her. It was causing me so much stress and anxiety, and it felt so wrong and horrible. I broke up with her because of it, and while it’s been a big relief, it’s been killing me that I had to lie to her. I told her that I wasn’t happy in the relationship and she asked if it was for any reason, and I just said no. She looked so lost and broken, and it’s all I could think about when I think about the relationship. It’s been weighing on my conscience so much, and I don’t think I can ever get over this feeling. I never felt worse about myself than when I lied to her.