While Stoicism is one philosophy to enable a person to be at ease with themselves it, in my view, is a somewhat spartan philosophy in that, from what I have read of Seneca's writings so far, it is more a matter-of-fact philosophy that discounts happiness.

I generally have found the pursuit or search for happiness transitory. Happiness to me is a fleeting thing. What I strive for instead is contentment. It is a more encompassing and satisfying state to pursue because the concept encompasses so many more emotions than just being happy

Oxford Definition:

Contentment: a state of happiness and satisfaction. "he found contentment in living a simple life in the country"

It is the pursuit of satisfaction with one's life along with a sense of happiness I feel really contributes to the well-being of one's health.