Bad people?

I've been working on a huge, possibly life-changing project - very advanced and challenging. Everybody around me knew about it and they were pretty supportive. Fingers crossed, go for it, you'll be famous, etc....

Now I've just finished about 50% of the project and once I let everyone know it's going really well - performing as advertised - the people became... I dunno, weird?

The responses are more like radio silence, changing subject, ignoring me, or even being hostile towards what I show them, pointing out every flaw they could think of without ANY (not even one) good word about the outcome.

At first I thought maybe the results are not as good. I've become paranoid, I couldn't sleep. I've distanced myself and today I know these results are really good. What is up with people? Are we really self-serving jerks who can't handle people when they face success they've worked for? Can it be it? Or maybe there is something I'm doing wrong? I don't get it. I wasn't bragging. I've just showed them what I did so far and told them it was hard but it's looking good, as I planned.