When playing competitively i was similar. My job was simply to stop other players playing, win the ball and give it to people who could play. However, as you get older your body just can't take the same physical abuse. If you're missing playing, go and try the walking football and then come back...
Spent over 30 years playing anywhere across the back 4 or defensive midfield.
Now, finally at the age of 57, my potential has been recognised and I play up front for an over 50s team :)