This is a ridiculous sequence of events:

Wake up, in a fairly positive mood, not exactly euphoric, but certainly ready to do battle with the day.
Have a pleasant and cheery telephone conversation with a friend.
Go out to run a few errands (post office, bank, etc.) - all easy and comparatively stress-free.
Return home, and realise that I'm in a miserable, self-loathing, and rather fragile mood, craving reassurance.

Why?  Nothing whatever in the preceding hours has been the sort of thing that ought to trigger such a reaction.  Even the queue at the post office wasn't particularly slow, or especially full of annoying people.

This sort of thing has been happening more often lately, which is a worry.  It's almost as though the only thing keeping the flow of positivity going, is a conscious effort to do so:  In other words, if I forget to constantly remind myself I'm a worthwhile person, the default state is an automatic belief that I'm a waste of space.  Which is daft.

Very glad I've got a shooting day tomorrow. A thing to look forward to, and (assuming I don't cock stuff up), something to boost the ego.

"I am a decent person.
I do have a right to be who I am.
Most people don't hate me.
I have at least some skill in what I'm trying to do"