I feel very intimidated by the consequences and the good outcomes of decisions, help?

I always think about my future decisions (mostly about talking to a girl I may be interested in) I always think about them deeply, and I end up deciding that there would be no way and I always back out of it, because the bad ouitcomes feel like they would outweigh the good ones. I'm not sure what to do, should I just not think, and just do? lol? I need to step out of my comfort zone, and need to realize that the bad outcomes don't matter if they don't even happen. So my problem is that I am so intimidated by the risk I am about to take that I back out last minute and Im hating myself for it now. I need help!