How is the lifetime of a star related to its mass?

Stars having less mass collapses early than those with more mass. This can be explained by Einstein's equation E=mc².
According to this equation, mass of stars is converted into light due to thermonuclear reactions occuring in the core of star which acts as engine of the stars. This thermonuclear reactions keeps star alive. Thermonuclear reactions occurs slowly in massive stars hence massive stars live more than light stars.

Perhaps seek some professional ? it isn't very asking some children who are just trying to find out answers to homework.also, it seems professional would actually be good to you. obviously it isn't going to magically fix your depression, but it'll do something. drugs, smoking weed, it won't do much, especially if your husband is against it. if you do it he'll dislike it. but talk to him, try and get him to listen to you, and figure everything out together, okay? there's a website- maybe it can offer some ?

Dust and gases contract.