Said Yes to a Relationship for Sex, Now I Feel Like I’m Hurting Her

Hey , I'm in bit of a trouble, a few months ago, I met this girl at my university. She’s more on the introverted side, but we hit it off and started talking. To my surprise, she was the one who asked me out and wanted to be in a relationship. Honestly, I didn’t think too much about it and, being a bit dumb and immature, I said yes mainly because I was interested in sex. Fast forward to last week-we finally had sex. It was her first time, and I could tell it meant a lot to her. We both enjoyed it, but ever since then, I’ve been feeling really guilty. She trusts me so much and genuinely cares about me, but I feel like I’m just using her for her body. I never really thought about what I wanted from this relationship, and now I’m scared to tell her the truth because I don’t want to hurt her. I know I messed up, and I don’t want to keep leading her on. But I also don’t want to break her heart, especially after what just happened