The overriding unconscious compulsion is what is meaningfully relevant here with regard to being gay or an addict, respectively.
The decision with whom to have gay sex or what drugs to use, respectively, isn't meaningful.
What's meaningful is that one's powerfully overwhelming unconscious compulsion to have gay sex and do drugs, respectively, are not consciously made "choices".
An addict is unconsciously compelled to do drugs.
It is not a choice.
Likewise, a gay person doesn't "choose" to have homosexual sex.
A gay person is unconsciously compelled to have homosexual sex.
Most adults don't either.
Interventions and treatment programs, societal taboos against drug addiction -- including keeping pot illegal -- play a major role in providing addicts with the external support they require to stop acting out their deadly addictions.
Your tendency to over-simplify into meaningless the terrible affliction of the disease of drug addiction comes at the sacrifice of the truth of the matter.
Though these are applicably similar, you wouldn't state that a gay person has a "choice" not to behave homosexually, as you realize how absurd that is to say.
But you'll say an addict has a choice not to behave addictively, even though the same type of unconscious compulsion is at work there.
The only difference here is that there is nothing wrong with being gay, but there is something terribly damaging and wrong about addiction.
Your convenient selectivity on the matter makes it obvious that your application of "choice" to the matter is simply an inapplicable contrivance you apply to suit your utilitarian purpose.