i can't stop so it has to be a disease?

addiction is technically categorized as a disease, it is a neurological disorder where something is imbalanced in the brain an once something is triggered it is foreseen as very hard to stop.
the false reality that an addict can just quit cold turkey is wrong. at this end of the spectrum it is said that addiction means "the loss of control over the use of a substance."

In the early stages there might be some choice involved, but once the addiction has set in, there is no choice.

being recognized as disease means:

• The illness can be described.
• The course of the illness is predictable and progressive
• The disease is primary – that is, it is not just a symptom of some other underlying disorder.
• It is permanent.
• It is terminal. If left untreated, it results in insanity or premature death.

it has been recognized as a disease since 1956