I appreciate your sharing your frustration and distress. I believe the key to bringing you back to center is through understanding the nature and necessity of positive and negative energies. Let me see if I can help you by painting a word picture.
Evil is simply a word created to "define" negative energy. It gives the impression that somehow negative energy is wrong, unnecessary, and is in noway bound to every person or thing. By the logic of the Universe and science, this is a grand misnomer. For life to exist there must be positive and negative energy. It is a must.
Throughout the history of the planet disequilibrium occurs, or an imbalance of energies. This is a natural part of living evolution, much like the ebb and flow of the tides. Therefore, chaos does have its place as an important natural order. Apply this knowledge to human behavior and remove the words always and never from your vocabulary, as they generate extreme images in the brain and therefore cannot be trusted. Then, step back and see the species as a whole and consider the positive and the negative - we (like all things) have both. You will likely start to notice a teeter tottering. Now, focus on the positive energy and ask yourself, "How do I contribute my energy to make a stronger positive influence?" When you can answer that question, your distress will subside and fill with purpose.