I wonder if a little tannin might help, too. I think what I'd do is pull a small sample and first add a bit of acid blend and see if it improves. Then see if a hint of tannin improves the bite. Even a bit of sweetening might improve it, although I don't usually like sweet wines.
You didn't say how much wine you made, but I usually add about a teaspoon of acid blend per gallon initially and about 1/8 tsp (or even less) tannin.
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