You need a heart which is in love, not an easy life, to achieve happiness.
Put your heart aside. Duty comes first. But when fulfilling your duty, put your heart into it. It helps.
It's true he was a sinner. But don't pass so final a judgement. Have pity in your heart and don't forget that he may yet be an Augustine, while you remain just another mediocrity.
Don't you long to shout to those youths who are bustling around you: Fools! Leave those worldly things that shackle the heart - and very often degrade it - leave all that and come with us in search of Love!
Is it not true that your gloominess and bad temper are due to your lack of determination in breaking the subtle snares laid by your own disordered desires? The daily examination of conscience is an indispensible help if we are to follow our Lord with sincerity of heart and integrity of life.