Happiness comes from Volunteer Suffering
Gain happiness through suffering? I know it sounds oxymoron. Take sports as a example, many who would wake up early and go through vigorous physical activities voluntary. To these individuals, there are no prizes at the finishing line. What they aspire and achieve is the happiness of going through the motion of completing the activity. Many would risk injuries, suffer both emotionally and physically. The happiness that these individuals want is the sense of accomplishment and the pride telling themselves that "I have done it".
Without certain amount of suffering there is no growth. Suffering allows us to test the limits of our body and mentally. I am not referring to suffering that cripples our life but sufficient to feel the discomfort that will not get us killed or paralyzed for life.
These suffering could be the important phone call that you have to make, the difficult subject that you have to study. You may not realize but by intentionally avoiding what you need to do, the emotional stress is far heavier than the stress of actually doing it.
If the task that you need to do so overwhelmingly large. Break it down to sizeable chunk and attack each chunk individually. The chunk has to be small enough for you do voluntary. By aggressively taking action, very soon you can cross off the task that you most dreaded of doing. That's how you grow. That's how you find happiness.