The loving yourself part must come before you can become a better person or more like the person you want to be. You have to want to do it for yourself and realize that other people don't define you. The moment we start giving them that power is when we start losing are true selves. Don't be so hard on yourself. I feel a lot of what you are describing and I am almost 45. So you have age on your side. Only time can heal the break-up part and that process is different for everyone.