If your parents are hard-core drug addicts, you won't likely get the most beneficial advice there, although they're going to learn about your problems one way or the other. I hope they will help you at that point to get proper diagnosis and medication.

In the interim, why not try the social services department in the local government in the city in which you live? Talk to a pastor if you can't get help with social services.
If that doesn't work, talk to a counselor in your high school whom you trust who may be able to get you the leads you need to get into rehabilitation.

You do have some serious problems with inability to say no to drugs. And it will get worse unless you take the initiative to do something about it now.

I am so sorry that you've grown up in the environment that you have, but you do have some authority to exert to get yourself clean of all drugs and to be out of a home where hard-core drug addiction is prevalent. Those things kill brain cells, and
I think we all feel that we need every one we've got!

Take care and continue to post to let us know how you're progressing in getting help. Don't ever give up the effort to get help. It may mean the difference between your living a good life or having a dependency that you do not want.

I admire you for taking this step to ask about what to do. Keep working on it; you'll get help, I feel sure.

Genetic