Maybe its not people are excluding you, but maybe they already have plans and maybe look into setting something up ahead of time. I know for me i never make it out to alot of Friday / saturday events mainly cause there posted the day off and im already busy.
As i get older married kids ect i dont have a ton of free time to just head out for hours on end on a whim. As much as i used to do that when i was younger i just dont have the time. I can if i plan ahead of time ( im old blow me)
Maybe try setting something up ( 2 weeks out 4 weeks ect) with a group of good friends. Hint hint
Also i agree on the working out, take out your frustration on some weights, benefit is you get in shape.