AFRICAN MIRROR REPORTER KHUSELA Diko has paid a loving tribute to her late husband, Nkosi Madzikane Thandisizwe Diko of AmaBacha, who was buried yesterday KwaBacha in the Eastern Cape. In a letter read at his funeral, Khusela described her farewell message to her husband, who died a week ago, as the most difficult letter she has had to write.  Nkosi Diko, 43,  died while in the middle of a controversy regarding an R125-million personal protective equipment tender that was awarded to his company but later cancelled.  Diko died after he denied any wrongdoing.  After the allegations emerged, Khusela was placed…