It is time you start to release all of your disappointments in life. They are not serving you in any manner. Hanging on to our "I should have", or our "I could have" only hurts us in the long run. Yes they can provide us insights on how to make better choices in the future in a certain scenario, but that is as far as their value goes. We all learn and grow through our individual experiences. You cannot learn and grow if you are still clinging to the past, which is not an area of life we have any power over. Carrying around your disappointment will only lead to your building frustrations and resentments towards yourself . Which only puts you into a state of weakness, where there is no clarity or power here.
Time to let go of our sense of disappointment with ourself. Realize you made best choice you had in that moment, with the information you had at that time. You need to hit the reset button. Let it go! Now you know better, hindsight always provides us more clarity about both a topic/subject as well as how we are as a person. . Beating yourself up for not making a different or potentially a better choice in that moment, only creates you second guessing and doubting yourself. Which hinders your decision making in the future, for fear of making a mistake. What we need to be doing is reflecting upon what we learned in that experience. What did it show us about ourself, our choices, along what we thought was available at the time, compared to what was really available to us in the moment, but we did not see? Doing this gives you the clarity, to trust that your next decision will not end up like the last. Time to accept we are all human, we will not already get things right out the gate on our first go around. It is okay to make mistakes, it is a normal process in life. Stop beating yourself up for that, as doing that as being harder on yourself is only prolonging your struggle and suffering regarding this. Which is not a necessary requirement for you to get the lesson, you Need. So learn to lighten up.