I Broke My Friend's Confidence...

So, I have this friend, Alex. We've known each other for years now, and even though we don't see eye to eye on everything, we still talk regularly... One day, while chatting over coffee, they opened up about a secret they were keeping from everyone else, they're planning on leaving their current job soon because of some personal reasons. It's not like Alex isn't stressed out at work; the company has been pretty rough on them lately with layoffs and restructuring... Anyway, Alex confided in me that this was hard to tell anyone but really needed a friend they could trust... I listened intently, nodding along as Alex talked about their plans for next month. When we parted ways, I felt relieved, I thought Alex would feel better knowing they had someone who understood... But then the day after, my phone buzzed with a message from another mutual friend, telling me she overheard us talking at the café and that Alex was really upset because someone else knew about their plans now... And it wasn't just this friend; turns out other people were aware as well. It seems I let a few too many ellipses turn into dots of my own without realizing it... So yeah, here's where the problem comes in: the message from this other friend asked me why Alex had been so upset after talking to me. In that moment, I panicked and ended up telling her that I was the one who let it slip, because she already knew something was off, anyway... The thing is, I didn't mean to do it on purpose; I just felt like this person would understand if they knew why Alex was upset. But now everyone's talking behind their back and wondering what else they might spill out next... It doesn't feel good at all. I'm not proud of my actions but here we are...