How do I know I made the right decision?

I met a woman a few months ago. We connected and a nice friendship grew out of this, but then I started getting feelings for her. When I told her about these feelings we talked about it and tried to maintain the friendship. We grew even closer and one night one thing led to another...
After that night (one night only) we managed to keep the friendship going, we kept doing nice things that normally couples would do. Because of that I couldn't loose the desire to get more out of this friendship.
Then we got into an arguement. She took something I said personal when it didn't have anything to do with her. We talked things trough but since then there was this distance between us. We didn't hug anymore, we talked in a diffirent way. It felt like a loss at that point but I still tried to remain friends.
But a few days ago I let her know that I couldn't take it anymore. I can't put aside my feelings and look at her like everyone else does.
I haven't heard from her since and I wake up every morning with the idea that I made a terrible mistake.
It's been a really long time since I felt like this and I'm doubting my actions now.
Should I seek contact and talk about it once more, or should I stick with the decision and try to forget her?