over eating, what is the problem?

I am in my mid 40's, healthy and happy. I exercise regulary and consider myself fit. I eat healthy but I am a junk food addict and drink pop by the gallon. I don't drink alcohal at all but feel I am as addicted to junk-food like an alcohalic is to the booze. I love the taste of pepsi like no other and have yet to have a hang-over or miss a day of work from drinking pop. I have been told that my excessive eating and drinking which has caused weight gain is a "mental" issue that needs to be addressed. So does a happy and healthy person need to seek a therapist? or how does one give up something they enjoy before it becomes a problem? I have tried the diet pops and drinking water but always come back to pop. I have been watching the tv show big medicine and see how excessive eating has deep rooted problems associated with their disorder. It seems so simple to just stop yet the patients are unable. I understand how difficult the life changes are. How does the over eater stop who doesn't have medical conditions and feels great? If some of my friends didn't mention my weight, I wouldn't give this much of a thought. Lastly, when should a friend feel they have the right to bring up the subject of weight gain or should we assume that each of us are aware of weight gain?

Happy but confused