Don't try and force her out of your head too much, your efforts are better spent elsewhere. Dreams do generally bring out the deep thoughts we cant/don't express in our waking lives but with this type of situation you cant remove all of that thought. The pain of her loss will be there for a long time and on some level you may always want her to come back into your life.
Accept what is, let go of what was, and have faith in what will be
