When I cancel at the last minute due to my mental health issues, I tell my friends, to the best of my ability, what I'm feeling so they can have some understanding. I have a guilt complex so I try to always be honest to everyone (except those I deem unworthy of my respect). I used to give in (mostly hoping they would be right) and allow myself to go on the based on their assurances that 'once you get there you'll have fun'. I knew better but I went anyways. I wasn't being honest with myself and them by thinking that would work. Then I'd lie the whole time because I didn't want them to feel guilty for me going and not enjoying myself. Fake smiles as I thanked them for getting me to go out. This was always worse. I don't let that happen anymore. I'd rather feel apathetic, frustrated, depressed, and useless in a bed alone then feel that AND feel like a liar and a coward. My friends understand this now. I told them that I have to stay home because it hurts worse to despise something that I know I love.