I work everyday but I'm not happy, is it worth it?

You have to find a purpose

I believe that no one's truly happy. Happiness comes and goes just like other emotions. It's just the state of your Dopamine, Oxytocin and endorphin levels at the moment. Life is stacked against us, as a primitive, evolving species. If you're happy all the time, you're broken.

I think two fundamental components to the happiness are health and exercise.
Not sure exactly where I've read this but a study shown that people that practice physical activity regularly (like jogging everyday) have overall in a better mood; Daily dose of sun exposure (aka not being indoors all the time) is also very good for your physical and mental health.
If you wanna go overboard there's also breathing techniques and meditation that helps relaxing and improve the mood ~