Counting the Frequency of Letters in a string (Python)

So I'm trying to count the frequency of letters in a user inputted string without using python dictionaries... I want the output to be as follows (using letter H as an example)

"The letter H occurred 1 time(s)."

The problem I have is that the program prints the letters in alphabetical order but I want the program to print the frequency of the letters in the order that they were given in the input...

an example of this would be if I entered "Hello" the program would print

"The letter e occurred 1 time(s)"
"The letter h occurred 1 time(s)"
"The letter l occurred 2 time(s)"
"The letter o occurred 1 time(s)"

but I want the output to be as follows

"The letter h occurred 1 time(s)"
"The letter e occurred 1 time(s)"
"The letter l occurred 2 time(s)"
"The letter o occurred 1 time(s)"

This is the code that I have so far:

originalinput = input("")
if originalinput == "":
    print("There are no letters.")
else:
  word = str.lower(originalinput)

  Alphabet= ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']

  for i in range(0,26): 
    if word.count(Alphabet[i]) > 0:
      print("The letter", Alphabet[i] ,"occured", word.count(Alphabet[i]), "times")

Solution

You could just check the input with if else and raise an Error if needed with a custom message

if original_input == "":
    raise RuntimeError("Empty input")
else:
    # Your code goes there

As a side not, input() is enough, no need to add quotes ""

Edit: This question was edited, the original question was to check if an input is empty.

Second edit:

If you want your code to print letters as in your output, you should iterate over your word instead over your alphabet:

for c in word:
     print("The letter", c ,"occured", word.count(c), "times")