I share your sense that existential angst is roughly equivalent to a sense of purposelessness. That said, a sense of purpose can come from a lot of places, not all of them philosophical. I know plenty of people who find a fulfilling sense of purpose in caring for their families, in performing their jobs, or similar things, without reference to more philosophical guiding principles be they theological or not. The happiest period of my life, for example, was between six months and a year after my stroke, when I’d recovered enough to not be profoundly depressed all the time but recovery was still my driving, fundamental, very concrete purpose.
I share your sense that existential angst is roughly equivalent to a sense of purposelessness. That said, a sense of purpose can come from a lot of places, not all of them philosophical. I know plenty of people who find a fulfilling sense of purpose in caring for their families, in performing their jobs, or similar things, without reference to more philosophical guiding principles be they theological or not. The happiest period of my life, for example, was between six months and a year after my stroke, when I’d recovered enough to not be profoundly depressed all the time but recovery was still my driving, fundamental, very concrete purpose.