I accidentally got myself addicted to my terminally ill relative's oxycodone. I was only 15 at the time, and I realized early on that it was only gonna be harder to quit if I waited to deal with it. I weaned myself off of it with my remaining stash for 2-3 weeks, but when I ran out I crashed into withdrawal, albeit relatively light. I didn't have a good time with that, especially since I didn't tell anyone.
If I were you, I wouldn't try what I did. Go get actual help from a doctor and professionals if you're totally hooked at this point. It's hard, but it's not gonna get any easier if you wait. You're not a criminal, people will help you.