It never does the opposite of your practiced thoughts and how you feel. So, it's important to pay attention to what you're really giving attention to. Every subject is really two subjects: what is wanted and the lack of it. And, how you feel lets you know which way you are looking at a particular subject. When you feel good, you're focused on what you want. When don't feel good, you're focused on the lack of what you want.
As a rule of thumb, whenever you receive an unwanted manifestation, don't define it as negative or wrong. Because it's not. Plus, when you say, "I wanted this, but the opposite happened." that's not the end of the story. How do you know that the opposite happening wasn't the path of least resistance way for what you want to happen?
For example, you want abundance to flow, you feel good focusing on money and abundance, and you receive a bill, and then feel frustrated because it seems like you got the opposite of what you wanted.
How do you not know that a bill coming would inspire you to focus more on allowing abundance, and so the bill actually inspired more money to flow into your life than had it not come?
You don't know because you took (negative) score too soon. Relax. And the let the story unfold.
Everything is always working out for you.
Just spin everything in a positive way (because it always is), and withhold your impulse to want to judge unwanted experiences or results as negative or a hinderance to what you want from coming. Just trust that what you want is still coming, regardless of how it appears on the surface.