I am slowly recovering from the devastating loss that I had this Sunday.
I played in my local club, it was a guy about the same age as me, rated 250 lower.  I had White and he played Scandinavian. I don’t quite like to play it, because usually it gives kind of easy piece play for black, also they bother my d4 pawn.  Though, I held my own well playing my only OTB game with it against almost 300 higher rated guy and getting a draw.
Getting back to Sunday’s game. The guy played Portuguese variation, here is what Chess Central says about it:
“The resulting play is sharp and trappy. An added benefit is the newness of the line,  which came into prominence only in the early 1990s.
Therefore many players of White can still be caught unaware, falling victim to an early knockout”.

This is exactly what happened. I spent a lot of time on the opening, finding the right moves.  The guy moved fast, looks like he played quite a few games like this one,  I spent essentially more time then him.  I was fighting on the enemy’s territory.  When I thought it’s time to attack, he suddenly created a mate threat.

I didn’t like h3 because of possible Bxh3 (not sound, of course, but I don’t like to defend such positions), so I played bad move g3, of course right after that I saw obvious Nbd2.

After 14. … f5, White were -.77.

The move looked like a placeholder, just putting the pawn on important square, so I thought I got a break, played Rac8 and was shocked by f4!. I don’t understand why I didn’t see it, as I made same move myself in the past (see for example post here about Marshall attack). It didn’t help, of course, that I didn’t have enough sleep the whole week and probably played too much correspondence chess, so I didn’t feel “fresh” when I came to play.

After that I lost a piece and the game went downhill. I resigned after 28 moves.

So, what can I do rather than just feel awful? I learned about that variation and I am playing a correspondence game with it right now.
Also, I realized that you shouldn’t be trying to find good moves in the opening  your opponent wants you to play. I actually did what Kramnik did twice in a row. Try to shift the game into the familiar direction, if possible.