I know this may sound stupid, but don't regret the last time you injected. Yes, it's wrong you shouldn't have done it. Obviously you should never do it again and I don't condone it. However, imagine what would've happened if you hadn't OD'd? Where would you be now, craving for the harder stuff or potentially dead. It's amazing to hear that you've turned your life around and made a decision to get your head in the right place and I hope the best for you in your future because damn, you seen where you were at, and you flipped the coin, you deserve it.
Good luck for your future and for all of our sakes - stay clean. ;)
All the best,