It is life threatening for sure 
Addiction is a progresive and deadly disease.
Going to see a doctor and ask for help is a good start! He can help with rehab ore medication to help you quit. In my country doctors has medical confidiality so he isn’t allowed to tell other institutes ore persons about what I share with him.
I’m sorry you are in rough waters now, a relapse is hard I had some too. We cannot do this alone. That’s why I’m here a lot. Maybe AA ore NA is an option for you? They also have meetings online. You can find them here:
Do you have the telephone numbers of your drugs suppliers on your phone? You could delete them? Do you have still drugs at home? Maybe flush that too?
You have options! There always are!
Like deleting all dealer phone numbers for instance?
Do not pick up the first one, not even a sip! If you are using alcohol you likely are going to use drugs too.
Did your partner know about you not drinking/using?