Happiness is not having what you want, it’s just wanting what you have. So choose to be happy for no reason. Want what you have. Happiness exists in the present moment.
Imagine that you could always have exactly what you think you want, instantly. In a short time you would be terribly bored. Without the possibility of not getting what you want, there is no game. So be grateful that there are problems.
Or just enjoy the process of pursuing what you want to create. Then you don’t perceive problems, but just aspects of an enjoyable process.