Usually when someone is drinking in an unhealthy manner it would most likely be due to something in their life that didn’t go well. Although, the reasons for drinking could vary. Maybe Rex had someone or something in his life he can never get back therefore the only way to solve his problem is to drink and try to forget it. In addition sometimes when things don’t go your way in life and it begins to feel as if that is the case over and over again there’s not much you can do and an easy way out would be drinking. Drinking is a coping mechanism for lots of people because it helps you forget and it helps you be in a state where your pretty much at a point in life where nothing matters anymore.
Use this if you’d like I didn’t put all the periods so maybe you could look over it and place them same as commas etc…