If you love the taste of black coffee, then maybe instead of quitting, you could just limit yourself to 1-2 cups instead? Or did even that much coffee have a bad effect? Another idea is to switch to decaffeinated coffee in the afternoon (assuming your problems with coffee come from the caffeine. If there is something else in coffee that is having a bad effect on you, then these things wouldn't help).
Black tea has more caffeine than oolong, which
>>2051 suggested. There are some flavored black teas out there too, but I don't know of any that would taste like coffee.