I'm the friend who bails at the last minute, again, because something came up at work and I let it win every single time. The dinner, the trip, the standing thing on Thursdays, I've cancelled them all. People have started to expect it, and a couple have just quietly stopped asking.
More people experience this than they realize.
You keep cancelling on people for work, and they're starting to stop inviting you.
If this sounds familiar, the Library can help you find the bigger picture.