I think there exists a terrible confusion about emotions in general fueled by pop culture. People should understand that emotions are just a form of motivation and not something magical. Unpleasant emotions don't have purpose to make you feel bad, they are here to help you to better adapt to your environment. Pleasant ones mean that you are well adapted. Simple as that. Also I would like to add that on the topic of happiness and other stuff related to positive psychology there is an excellent course from prof. Tal Ben-Shahar.