I hate to say I've been in your shoes, but I have.....and I thought it was the end for me too. Alcohol is awful to withdrawal from, add in the coke and you've got your hands full. I agree that seeking medical advise would be smart. I however quit without my doctors care, it took a lot of self care, rest, and the determination to never do it again....period.
When I felt really bad, like you do now, hot showers, hot soup, and a warm bed. That was it for 3-4 days. Then I slowly was able to go out to walk around and go food shopping. I was off of work for about 10 days, it took that long to feel human. I never told them anything, except that I needed some personal time off. No need to share with the boss.
You're on day 2...keep going and never look back. Don't repeat!!