Why my total income adds the severance payment (box 67) with box 14 when my box 14 already shows my total severance package. Did my employer made a mistake on my T4?

It appears your employer has made a mistake on this T4 slip. Box 67 will transfer to the T1 General Line 130 - Other Income, whereas Box 14 is entered on Line 101 - Employment Income.

In order to fix this, you'll need to contact the employer and have them issue you an "amended T4". A copy of this amended slip also needs to be submitted to CRA.