How did the Vietnam War influence the social structure and lifestyles from the 1960s counterculture?

There are a number of factors you could look at relating to social strcture and lifestyle of the 1960s counter-culture. First, consider the impact of the war being broadcast on television. For the first time, Americans in their living rooms were exposed to the reality of war. Body counts were published. The impact of this was horror, shock, and disgust for many people which fueled the rebellion.

You can't ignore the music of the counter-culture. There were protest songs, such as Country Joe McDonald's "I-Feel-Like-I'm-Fixing-to-Die" or Crosby, Stills, and Nash who wrote several protest songs based on Nash's work with Vietnam Veterans.

You could also look at the effects of protests against the war and their outcome. Consider Kent State and the violence against students in 1970 or peaceful protests like the "Human Be-In" at the Golden Gate Park in San Francisco in 1967.

And of course, there is the rampant drug use both by soldiers and protesters, ranging from marijuana to psychotropic drugs. Wide-spread use to escape reality or to seek enlightenment through pharmaceuticals lead to tighter drug laws in the US in the 1970s and 1980s.

Hope this helps!