Yawn all the time without the satisfaction, is that caused by long exposure to second hand smoking?

Likely not: It means that you don't have enough sleep or not have a restful sleep the night before. If you have at least 8 hours of sleep and still feeling tired, the most common cause is obstructive sleep apnea. Second hand smoking might cause COPD or chronic obstructive pulmonary disease. Severe COPD might cause chronic hypoxia / hypercapnia and makes you drowsy all the time. You are too young for copd.