At the end of the day, if someone wants to be in your life, they will be. Truly — they are capable, they will make the effort, they will show up. If they do not — let that be your closure.
However, you do not have to hate them. You do not have to remember their contribution to your life as anything but beautiful. Do not ruin them in your mind, do not grip until you feel resentment. Instead, love them without attachment. Love the lessons they taught you. Wish them well every single time you think about them. Miss them, but do not ache for them to come back. If the people in your life left because they were not ready to value you, or love you, or be there for you, do not wish for them back, do not ask for them to be more than they can be at the moment. Wish for them to figure themselves out. Wish for them to grow. They are on their own journey — a journey you are not a part of. And that is okay. You have to learn that that is okay.
So instead of focusing on the people who left, focus on the people in your life who have chosen to be there. Focus on the ones who stayed, on the ones who appreciate you and respect you. Focus on the people who match the love you give them, focus on the people who empower you and grow you and make your life beautiful. You are surrounded by human beings who will not shy away from the love you give. You are surrounded by human beings who know that they want you in their life, people who show you that every single day. Do not take them for granted. Do not lose touch of what you have, chasing what you no longer do.
Trust me when I say — you will miss out on beautiful things if you continue to stay rooted in all of the ways you were wronged, if you continue to let your past pull you from experiencing what the present has to offer you. Do not close yourself off to your potential. Instead, open yourself to the world, and allow for it to fill that space with the kinds of people, the kinds of moments, and the kinds of experiences that exhilarate you, that compel you — that make you love yourself, and your life, and what you have to offer, more and more each day.