Check your acidity. I'm no expert, but I have observed that when I detect that off-putting medicinal flavor in must or fermented wine, the problem is usually that there is not enough acidity. My advice would be to check pH and TA then do some bench trials with a bit of tartaric acid addition. I had that problem last spring with a Chilean Syrah and a bit of tartaric acid did the trick. Seems to be coming along nicely now.