I think your on a very great path to contentment and happiness. I agree with you that some things are out of our control, and others are within our control. I think a key to being happier is controlling what we can, and accepting all other externals as they are. Memories of past events can be very helpful. It helps us learn how to respond to future problems. However, learning to be scared of certain things can be unhelpful at times. For instance, when we think we are going to relive a very rare instance in our lives, we can be giving that “very rare” phenomena too much power. We must learn to rationalize and challenge those thoughts and feelings. Then, we can still remember, but have all the tools we need to respond in healthy ways. During world war 2, there was a psychiatrist locked up in Aushcwitz. (worst nazi death camp). His wife was taken from him, his possessions, his friends, his clothes, his hair, his life. He concluded after being released that there is one thing no one can take from someone. He argued that in “between stimulus and response, there is a small space. That space is our choice of how we respond to that stimulus.” His name Viktor Frankl. We can’t control everything, but we can control how we perceive it, process it, and respond. If someone talks bad about you at work, respond by saying : I don’t feel bad about them, I’m sorry they feel that way about me. Why?: because I choose to act. Not react to others. Have a great day.