Want to know something? Mothers have the special 'Nag' ability. Unfortunately some simply take it as 'Where did I go wrong with you' rather than look at the problem being in them.
Mind you, the Rational Adult faults himself first, and others later. However, shifting the blame is something everyone does. Solution to the problem is generally looking at it from the outside. My mother's a genius in tearing apart my self-esteem, but I'm a tough bastard born to conquer the world, so I build it back up the moment she tears it down.
The trick is letting the thing rest for a day or two. Your brain will automatically come up with enough excuses to bring your mood back up to full power, or outright push the nasty thought at the back of your mind.
Humans aren't made to be depressed, and they aren't made to be cheerful. They're made to be durable.
Grit your teeth and march on, you'll soon feel better.
Another thing is simply screaming your anger out in the middle of nowhere.
That works miracles too.
Update, and slight offtopic (it should belong to WTF thread now): I'm really starting to suspect she has BPD or something. It's been three hours between the initial conversation and another call, and she went from being stand-offish and degrading to entirely sanguine. Not the first time I've observed that, either. It feel kinda like a malfunctioning Skinner box that occasionally starts sending shocks despite the conditions not changing.
The thing is, in that situation, as in others before, I've already blamed myself, quite rightly, for a minor problem (I wrongly memorized the time a class starts, and by the time I found out, I've already been late half an hour, so I need to find the professor and ask when I can catch up) that transpired. And as I was right in the middle of fixing the situation, I got the call during which I got treated as though I didn't realize I dun goofed and got torn apart.
I'm pretty tough, or should I say, calloused, myself, but the issue was not with a ruined self-esteem but with the absolutely unsympathetic way the beatdown was delivered.