I Shared A Secret That Made Him Look Elsewhere

So here's the deal, I met a guy online while I was in a bit of a down period. We hit it off over shared interests and found ourselves talking for hours every day. He’s a military man stationed overseas, and he's currently on leave back home, so we've been dating casually since he arrived two weeks ago. We’ve had some great moments together, dinner dates, movie nights at his place, but nothing exclusive or serious. Lately, though, I've felt this nagging guilt over something from my past. See, before meeting him, there was this one time when I went to a party with a friend and ended up getting really drunk. It wasn't like me, I don’t usually do that sort of thing, but it just happened. And because I was so out of it, another guy took advantage of the situation. We didn’t have full-on sex or anything serious, more like groping in a dark corner while everyone else was dancing and drinking. Afterward, I felt awful about myself, but I never talked to anyone about it until now. When we started seeing each other casually, I thought maybe if I opened up more, I could be vulnerable with him. So the other night, after some wine and late-night conversations filled with laughter, I told him about that party. Now, he’s been distant since then, even though everything seemed fine before. I’m not sure what to do, I feel terrible for bringing it up and maybe ruining things, but at the same time, if we’re going to be honest with each other, shouldn’t these kinds of stories come out? Am I being too much? Is it normal to bring up something from your past like this? What’s a good way forward?