Expertimental batch sucks. What do?

I recently made an experimental batch.

Approximate Recipe: 1.75 gallons, 3lb mixed red and green grapes, 1.75oz Corn Sugar, 1lb sugar, 1tbs "maple syrup", 10 grams Redstar Curvee' yeast. Specific gravity of 1.032.

Last night I racked to the secondary and made a few changes because it tasted watery as fawk. I added 2 tbs tannins, 4 tbs yeast nutrients, and 1 cup of sugar, and around 4tbs "maple syrup" (its all I had) I gave it a good swirl and its doing its thing. The problem is I believe it is still going to suck. How can I fix it? Should I get more grapes? I had thought about some 100% grape juice. I don't really want to dump it, but I certainly do not want to bottle it in the condition it is in.

You could use frozen grape juice concentrate. This would really pump the flavor up and not add to much liquid. When I make apfelwein I use apple juice concentrate to back sweeten. 100% grape juice would work also but it would probably take more to get the flavor.

thats what I will be doing then. I will then age her out.