Supply decreases

I have been sick with a cold for about 2 weeks. I avoided taking anything due to breast feeding but at the end of this week it was so bad I couldn't not take something. I took cough medicine a couple times and then Friday night I took NyQuil after she was asleep for the night and I knew I'd have a while before she ate again. Since then my supply tanked! How do I get it back. I'm still sick and going to the doctor Tuesday finally. I haven't taken anything since again because I'm so scared of losing my supply all together.