I've spent a lot of time pursuing happiness and meaning in my life, but I've realized it's a moving target and that it happens in the moment. Happiness is not a goal in itself, but rather a by-product or side-effect of something else. But what is that "something else" then?
One way of seeing it is being useful and doing more things that have a positive impact on other people, the environment and the nature. The Purpose Of Life Is Not Happiness: It’s Usefulness is an insightful article and one of the best I've read on the subject — and a good reminder not to overthink things. Do more!