Binge drinking is consuming a large amount of alcohol in a short amount of time, resulting in intoxication. Alcoholism is a chronic physical and/or mental dependency on alcohol in which the user has a high tolerance to the effects of alcohol and typically experiences withdrawal symptoms when they do not consume their accustomed levels of alcohol. You can binge drink quite frequently without being an alcoholic, and many people are lifelong binge drinkers without ever developing alcoholism. Although it would be difficult to be an alcoholic without at least occasional binge drinking, there is still significant variation of binge drinking behavior among those who suffer from alcoholism. Neither term is inherently derogatory.
Diabetics do not go into comas because they give into a craving for sugar, they go into comas because they have a hormonal disorder that limits their ability to regulate the level of glucose in their blood, and controlling that level artificially with exogenous insulin is complicated and difficult. Comparing diabetics to alcoholics in the way that you have done is disingenuous and does a disservice to both groups of people. And diabetes may not carry the same stigmas as alcoholism, but it most assuredly does carry its own set of stigmas.
Should Kelvin reduce his alcohol intake and be wary of developing alcoholism? Absolutely. Frequent binge drinking does put you at higher risk of developing alcoholism than the general population. But your accusatory suggestions that he’s really just a closet alcoholic who’s too weak to admit this fact are ignorant and offensive, and your understanding of diabetes clearly is insufficient for you to compare it to other diseases. If you want to contribute to this discussion in any kind of meaningful way, you should educate yourself first.