It will always be painful, you will always miss and love the person you lost. But the intensity of the pain and the overwhelming preoccupation changes. And that isn't really your choice. It's a natural organic process that you're not in charge of. The only thing you can do is find ways of supporting yourself to navigate that process as it comes through your system. It’s important to allow that to happen.
If we don't forgive ourselves for our mistakes, and others for the wounds they have inflicted upon us, we end up crippled with guilt.