Evidence continues to support the theory that anorexia involves excessive habit development. The habit of food restriction doesn’t occur overnight, but does occur over time after the initial effortful attempts. Drawing parallels to you and everyone else, it’s rather suggestive that dedication to a diet, a goal-oriented focus, and classical learning will eventually turn willpower to habit. Change is difficult, but if you stick with it, things get easier.
Being underweight is associated with an increased risk of death, just as being obese is, but the causes are fundamentally different. The risks of obesity are owed largely to having too much fat mass, while those of being underweight are owed primarily to having too little muscle mass.
Regardless, being underweight is nowhere near as large of a health concern considering how much more prevalent obesity is.