In Kafka's short novel, Metamorphosis, he absolutely addresses the idea of self-created happiness. Gregor believed himself to be happy when he was working for his family's income. It was the thing that he knew how to do best and he liked having a constant something in his life. However, when he went through his metamorphosis, he realized that working at his job did not provide him happiness and he couldn't manufacture it just by helping his family.
I think his metamorphosis was in some ways a relief to him because he finally felt that he could figure out what he was really supposed to do. He was still the same person (fundamentally) and still enjoyed the things he had previously, such as art and his sister's violin playing. Gregor expected that after all he had given to his family over the years, they would help him in any and all ways possible after this difficult transformation, however, they basically tossed him aside to fend for himself. In that regard, Kafka shows that even though we may take the right steps to happiness, we cannot always create it for ourselves.
Kafka goes even further in this assertion by causing Gregor's death. Gregor realizes that he has become a burden on his family and he no longer wishes to create such stress. Though he was under the impression that they loved him, he suddenly realizes that their love did not go any further than their pocketbooks. It's a bold assertion on humanity that causes us to really wonder if working hard for our families and loving them will really ever be enough if we need them just as much one day. It certainly says something about the importance of trusting or not trusting the people around us.