Difference in value of the columns

I want to find the difference in the value of the metrics between the indicator H and L in the below table.

    ID      METRICS  INDICATOR    
    1        204.4 
    2        205    
    3        206        H
    4        204    
    5        199
    6        198        L        
    7        204    
    8        205        H    
    9        201    
    10       199
   The desired result should look something like this

            diff            reversal
  (206-198)  8               H

  (198-205) -7               L