How I become an awful person because of this? Because i feel like i am right now.

I’ve been talking to this girl for 3 weeks now and she’s a nice person, very cute and i like talking to her. I was a virgin and never had sex and wanted to get experience and i did after 3 weeks. She seems kinda into me but i’m still not. When i first started talking to her i wanted to see where it goes but i wasnt really feeling anything towards her. I talked to my friends about it and said hey i dont feel like im into her so i should probably cut it off right and they said just keep talking, sometimes feelings doesn’t happen quickly it happens over time and have sex and usually after sex feelings come up and i was like okay. I never had a relationship too. I waited for 2 weeks to get to know her more and we did it. It just happened. We talked about what we want from this and i said im not sure and dont feel ready for anything so lets keep talking and she says she might want relationship but she’s still not sure too. But i still feel awful because I honestly feel nothing. It seems like I basically used her for sex. I dont know what to do. I dont want to have sex with her again because of this. I still would want her as a friend tho shes a very sweet person that i can get along easily but if that would make things worse id rather have proper talk with her and cut off if it would be for the best but as i said i dont know what should i do.