Blunted22,

When leaves curl upward like a taco there might be a magnesium deficiency... u might try soaking 1tblspn of epsom salt in a gallon of water and do a foliar feed... that will be a temp fix... u will have to add some Mg (if that is the deficieny) to the soil..

But if you have been overwatering and your soil has been wet for too long, then root rot could be causing the browing. To verify root rot, you can simply inspect the roots to see if they are browning instead of white. Good Luck.....