To answer your question, yes.
I would reccomend a yeast nutrient/fresh yeast combo for that, but first you should try to let it sit for awhile. If the initial fermentation is done (take a sample and chk if you can) you may just have 'young wine'. Young wines taste a bit harsh, but will develop with age. If you can stand to wait, (I know how hard it is!) give it a month and see if it gets better. :-)