Does great sex happen overtime? Or in an instant

I (18M) and I’ve recently started sleeping with my girlfriend(18F). We’ve tried twice now, and both times didn’t go the way we hoped. The connection just didn’t “click” yet, and now she’s starting to feel like maybe we’re not compatible, which really hurts to hear.

She’s been feeling insecure because things haven’t flowed naturally and also the fact that i’ve been with multiple women before and I think she’s starting to doubt herself — like maybe she’s doing something wrong, or I’m not fully into it. But I care about her deeply, and I want this to work. I just think we’re both nervous, probably overthinking it, and putting pressure on ourselves.

I’m starting to feel guilty about the whole thing too, even though I know that good sex takes time, comfort, and communication.

Has anyone else gone through something like this early in a relationship? Did things improve over time? How did you help your partner feel more secure and rebuild that connection?

I really want to be patient and figure this out with her, not let it ruin something meaningful. Any advice or shared experiences would be appreciated.