Be honest. Did I screw up? Daughter having sex without condoms

So. My daughter is 17. Shes been dating her boyfriend- he's 18- for a few months now (My rule was no dating until after high school but she hid him.) His parents are on the stricter side like I am but they're very religious while i am not.

Not long after I discovered her secret relationship, I also learned she was having sex when I found her condoms.

I told her I was glad she was being safe, but I grounded her for having sex. I feel she's too young. I told her how hurt, disappointed, and angry I was. I told her I felt like a failure. I’ve had talks with her since he was 11 about sex and why it’s best to put it off until you’re older and in a mature relationship. I didn’t ban her from seeing the boyfriend, but I restricted how much time they could spend together and where they could be together without a group of friends.

We just got back from a family gathering. My daughter was already in the car, she’s been driving for me because I’m injured. She asked me if I could go back and get her phone that she left. I went to get it and saw all of his text notifications from her boyfriend. I read through it because they were talking about sex. I’m not gonna go into detail, but they are not using condoms anymore. They both agreed condoms are “evidence” that shows they still have sex if they're caught with them again.

My goal wasn’t to demonize condoms or safe sex. It wasn’t my intention. It was to stop them from having sex. I don’t know what to do.