One of the bad consequences of chemical dependence is that it ruins relationships with persons like yourself. Many unfettered chemically dependent people finally acknowledge that they are addicted when significant others, such as yourself, will not tolerate any further drinking or using. Once addiction is recognized or acknowledged, recovery is not far off. Drinking alcohol and using drugs are voluntary behaviors for the purpose of gaining physical pleasure from the substance. Anyone can quit an addiction, immediately, and for good.
Addiction is a state of chemically-enhanced stupidity which can be overcome by abstinence.
Your loved one does not suffer from a disease that causes him or her to drink or use drugs, or which prevents him or her from immediately quitting altogether. You carry no burden of change. No one does. You may be so dependent on that person for love or approval or something else, so dependent that your own well-being is overshadowed. But that is not a disease.