Muttley is right- you are better than 95% of the population of Glasgow, who stayed in bed this morinig, or vegged out in front of the TV.
Maybe you should either: accept that you do this for fun, and enjoy the day without stressing too much about the time OR; change something- join a club? change the way you train?
I am one of those who stares at their watch all the way round, struggling to beat some pre-determined target, and it takes all the fun out of the day...........for that reason, I've given up on halfs, and even to an extent marathons, and now do trail races/ ultra's etc, where you have no idea what time to aim for , and just enjoy the day. What about trying trail races instead, take the pressure off time- wise, and just enjoy?