In my opinion happiness is not a goal but a state subject to change. I stopped looking for happiness and started to train contentness. Being satisfied with something less than optimal will make you feel much better over time. Sometimes things will go sideways independently of your control. You can be all stoic about that and pretend it doesn't faze you; in my experience it's better to find and focus on the little things that make life more bearable, like preparing a hot meal after a shitty day instead of crashing on the sofa and conteplate the injustice of life.