I'm pretty much 2 for 2 on making Cherry Melomel's that taste like cough syrup. I'm still letting them age.. maybe they will improve. But I don't think I'll make it again.
They've had decades of flavouring coughsyrup with cherries, and still can't get it to not taste like cough syrup... good luck! ;-)
As a side note - why do they persist in flavouring medicines with cherries, when orange flavours are so much more pallatable in that situation? Sorry to hear about your mels, how long have you had them aging?