it brings to mind "The Road Less Traveled By"
my opinion- your dream seems to be a compilation of both your self woth and your view of the world around you the running figure being both yourself and your assessment of the other sheep in the flock the nets and cardboard trees seem to be ominous rumblings of your contempt for the fake life you live unhappy and also incomplete. the pain in your sides in not from running i would think but from tiering and wishing the road would become less dismal a needed beacon on the horrison that you have not found the ruined building being that once bright beacon but only an illusion of happiness that you see as your goal but upon arriving see that the road you travel is not worth the effort. maybe the dream is a message telling you to reassess your life and find your beacon.