The more research that gets done on addiction and substance abuse the better we can understand both what is going on and how to treat it.
Dr. Helen Fisher is a biological anthropologist at Rutgers University and she has studied love in over thirty cultures across the world. She believes that love isn't so much an emotion as it is a powerful drive. Dr. Fisher has done MRI scans of people in love and has found their brains look remarkably similar to the brains of people on addictive drugs.
This is partly why I am always encouraging parents to be positive with there kids when they are in recovery. If you can look for the good and talk about it you are feeding the brain the same kind of reward that it was getting from drugs and alcohol. Drug and alcohol us robs us of our ability to get pleasure from normal things. Hearing positive comments from those that care about us (love) goes a long way to rebuilding the brains ability to respond in a normal fashion
This is true too for the recovering person. Paying attention to what is good in our world helps us get better. We all get very good at picking out negatives, we need to replace that with the ability and the habit of seeing good.
It takes practice.
Work on it.