How can I replace duplicate strings with increasing order in T-SQL?

I have a single row table:

Id | Description
---------------
 1   #Hello#, Its 5 am. #Hello#, Its 9 am. #Hello# its 12 pm.

I want to replace these duplicate string #Hello# with an increasing order. I need output like

Id | Description
---------------
 1   #Hello#, Its 5 am. #Hello1#, Its 9 am. #Hello2# its 12 pm