Each day we are striving to become our best, but life happens. We get upset. We get frustrated. We get depressed. We allow other people or circumstances beyond our control to have a greater influence over our lives than they deserve. Why is this? It is because we do not build our decision-making processes on solid ground. How does solid ground relate to our feelings? Because we base our decisions on emotion instead of principles. To live basing decisions on principles gives you a filter to run every decision though and allows you to make the best decisions for your life, and not just the best for your life right now, but for the long term. These principles are where you begin to construct the life you want.
The principles you choose as your foundation for your life, your relationships, and your business interests set the course for your future. More often than not your outcomes will be beneficial to you. Sometimes they may not, but each outcome that does not work out becomes an opportunity for reflection. Did I properly apply my principles, or did I let emotion, enthusiasm, fear, etc. get in the way? If you stay true to your principles, at the very least, you will have peace of mind after every decision even if the outcomes do not work out.
We are humans. We all have emotions, and they can be strong and overwhelming. They have helped us survive to become the dominant species on the planet. Yet every animal has emotions. Not every animal has the ability to think and value the long-term play over the short-term satisfaction of quelling an urge. Your emotions are good and natural, and you should never feel bad for having emotions, either exceedingly positive or negative. However, once you recognize you are feeling an emotion you must let it go. You have a life to live. An important life that will affect countless others. It is your one chance to leave a legacy on this planet and that legacy will get left no matter what. The choice is yours to decide what it will be. Just as your legacy will be timeless, the best principles are also timeless. They have served us well for ages and will continue to do so. So give it a shot! Write down the principles you want to live your life by. Evaluate each decision through that lens and see how life turns out.
A great resource on principles is the book Principles by Ray Dalio.