This our code we want that whenever we do the letter it shows in the LCD and when we change to anther move the previous one stay with the new one near it
I did not try to follow all of your code but the problem may lie in the fact that you are repositioning the cursor to the beginning of the second line each time around the loop.
Also - what effect do you think the lcd.setCursor(2,2); statement will have when applied to your 16x2 display?