Drug Addiction and Social Anxiety

Hey. I've been addicted to klonopin, marijuana and alcohol. I've always wanted to join a 12 step, but my social anxiety and agnostic atheist beliefs have always kept me from doing so. My therapist thinks I'm ocpd. I personally identify with apd more. I don't know what to do about my fear of people. Has anyone else here overcome fear of social interaction? If so, what was your experience like? I usually get discouraged every time I go and abandon the situation. I just need advice.

Attending an AA meeting for the first time can be scary. It was the bottle (actually the disease of addiction) inside of me that was more afraid and felt threatened by possible recovery. It helps to not feel so alone if a friend goes along with you. Get a cup of coffee/decaf and find a seat. The meeting lasts about an hour.
You don't even have to be an alcoholic to be present at an 'open' meeting. Closed meetings ask that only admitted alcoholics attend, but even most of them are lenient about this rule. Anything that spreads the word and saves lives is good IMHO.
They may ask if there are any newcomers attending AA for their first time. You don't have to answer if you don't want to. If you do, your first name is fine. Just say that you are 'here to listen'. The room will say 'Welcome' to you.
Everyone in that room had a 'first time' once and they were likely as afraid as you. It is a big step having to face recovery. It can change your whole life. It can be a threat to your disease of addiction.
Take some pamphlets home with you if they interest you. Books are at cost. Become more familiar with the program. It may be hard to break the ice, but get to know people and let them get to know you. It is a "we' program. AA works together to get sober and stay sober. Many have phone lists for reaching out.
I tried my hardest to quit drinking on my own, but I could not do it alone. I used to consider it my own personal problem and none of anybody's business. That way of thinking just got me sicker.
Many members have problems with accepting a 'God' (power greater than ourselves) for whatever reason. You don't need to have any religion at all to be a member. A sense of spirituality may be useful, but really that may come later.
See the chapter in the Big Book, We Agnostics:
https://www.aa.org/assets/en_US/en_bigbook_chapt4.pdf
AA saved my life. One day at a time.
Best of luck to you.