A major survey on this subject found the following;
" of 127,545 American adults found that married men are healthier than men who were never married or whose marriages ended in divorce or widowhood.
Men who have marital partners also live longer than men without spouses; men who marry after age 25 get more protection than those who tie the knot at a younger age, and the longer a man stays married, the greater his survival advantage over his unmarried peers"
As for those in long term partnerships but not married they found;
"living with unmarried partners tend to fare better than those living alone, but men living with their wives have the best health of all"
"Japanese scientists reported that never-married men were three times more likely to die from cardiovascular disease than married men. And a report from the Framingham Offspring Study also suggests that marriage is truly heartwarming. Scientists evaluated 3,682 adults over a 10-year period. Even after taking major cardiovascular risk factors such as age, body fat, smoking, blood pressure, diabetes, and cholesterol into account, married men had a 46% lower rate of death than unmarried men."
"Mental health is the most prominent; married men have a lower risk of depression and a higher likelihood of satisfaction with life in retirement than their unmarried peers. Being married has also been linked to better cognitive function, a reduced risk of Alzheimer's disease, improved blood sugar levels, and better outcomes for hospitalized patients"
These results have been found in multiple studies.
So the evidence suggests your health will be better if you marry, but you are an individual and should do what you want. But don't turn your back on the idea of marriage because you believe you will be healthier if you don't, because that is not true.
As one wise old saying goes "a trouble shared is a trouble halved"