The leaves are black
Have you checked your plant for pests? It maybe aphids or a cutworm. You could try giving it a soap bath ( mix some dish soap , just a couple dropsin in a spray bottle and water ) and spritz this on both sides of the leaves. It may help.
Sounds like a cut worm, turn your leaves over and look for pests.
You could spray lightly soapy water on both sides of the leaves. Another alternative is neem oil.
You could also take a sample leaf to your garden center, they could help you identify what is doing the damage.
That’s good and you can make wine or jam.