watering every 2 days is a lot unless the soil really is dry that quick (not the surface of the soil, but a few inches down), you shouldn't be watering your peppers until the leaves start to wilt a little (in the morning). You need to stop giving it extra water, if a plant is wilted with moist soil extra water will never solve the problem, it could exacerbate it.
Â
It's probably a fungal issue from too much water, you need to let the soil dry out, it may be too late to save it. As someone else mentioned, repotting may help. Â