Telling my doctor wasn't really a choice for me as I was admitted from an ER visit for a different reason. I then was held for a detox because they couldn't legally let me leave without releasing me to someone's care and my wife refused until the detox was done. Seeing my GP afterwards, she already knew the point I had arrived at so maybe it was easier to come clean on exactly how I had gotten there. In the end I felt relived and she was very helpful on what my treatment course should be and what we should watch for. I think you should remember that as a physician, they've seen it all before and will see it again.