Brush Opacity issues

I cannot figure out what's wrong with my brush. It takes two or more strokes to get the full opacity of a color and I can't figure out how to change that. I've googled and messed with all the opacity settings. They're at 100%, my wacom pen pressure is up, I've made sure my layers are normal and that they are also at 100% opacity, but nothing I do changes my brush opacity. I've even tried using different brushes, but it's always the same.

Please help me, I have work I need to do.